# Calculated Industries 5025 ElectriCalc LT User's Guide 48 Pages

Calculated Industries ElectriCalc LT is a versatile tool designed to simplify electrical calculations and enhance productivity for electricians. With its intuitive interface and specialized electrical functions, it streamlines complex tasks, saving time and reducing errors. Utilize it for various calculations, including voltage, amperage, wattage, power factor, and theoretical horsepower. Determine appropriate wire sizes based on ampacity, voltage drop, or parallel configurations.

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**ElectriCalc**

**®**

** LT**

An Electrician's Utility for Wiring

# User's Guide

**IMPORTANT NOTE ON**

**USER RESPONSIBILITY**

Due to the serious nature of electrical installations, the user of this calculator must be certain that he or she is using it correctly, i.e., in accordance with both the following instructions and National

Electrical Code

®

requirements.

This tool was designed to work with the

1999 NEC

®

, not replace it. Users, especially those unfamiliar with the Code, should exercise appropriate caution.

If questions arise as to the correctness of an answer given by the calculator, or if an answer appears to conflict with the

Code, the user should always defer to the Code.

If used responsibly and correctly, this tool will save the user hours of tedious calculation and look-up time, reduce material costs, and provide safe, accurate, Code-legal answers.

National Electrical Code and NEC are registered trademarks of the National

Fire Protection Association, Inc.,

Quincy, MA 02269

Introducing the

**ElectriCalc**

**®**

**LT**

The ElectriCalc

®

LT is an invaluable calculator for today’s busy electrical professional. Unlike a regular calculator, it has intuitively labeled “electrical keys” and conforms to the 1999 National

Electrical Code, allowing you to solve

Code-related problems quickly and accurately. Common NEC tables are built in, providing instant solutions for the following:

♦

Volts, Amps, Volt-Amps, Watts, kVA, kW, PF%, EFF%, and DC

Resistance

♦

Copper or Aluminum Wire Sizes

♦

Parallel & Derated Wire Sizes

♦

Voltage Drop Wire Sizes, % and

Actual Voltage Drops, Voltage

Drop Distances and Wire Resistances

♦

Grounding Conductors Sizes

♦

And much more!

**User's Guide — 1**

**Table of Contents**

**Key Definitions ................................................. 3**

**Default Settings .............................................. 16**

**Basic Math Operations .................................. 17**

**Percent Calculations...................................... 17**

**Memory Functions ......................................... 18**

**Kerchoff’s Law................................................ 19**

**Ampacity Wire Sizing..................................... 24**

**Voltage Drop ................................................... 31**

**Error Codes..................................................... 39**

**1999 NEC References..................................... 39**

**Battery Information ........................................ 40**

**Settings ........................................................... 40**

**Warranty .......................................................... 41**

**Legal Notices .................................................. 45**

**2 — ElectriCalc LT**

**Key Definitions**

**Standard Calculator Functions**

**[On/C] — On/Clear**

Turns on power. Pressing once clears the last entry and the display. Pressing twice clears all non-permanent values.

**[Off] — Off**

Turns all power off. Clears the memory and most internal registers.

**[Set] — Second Function**

Accesses the secondary functions shown above the keys when pressed prior to selection.

**[Rcl] — Recall**

Recalls a value stored in a register

(e.g., to recall voltage drop % press

[Rcl] [VD%]).

**[Rcl] [Rcl] — Display/Clear Memory**

Displays and clears the value saved in

(M+).

**[Set] [Rcl] — Clear Memory**

Clears the value saved in [M+] without changing displayed value.

**User's Guide — 3**

**[M+] — Cumulative Memory**

Adds displayed value to Memory (e.g.,

10 [M+], 20 [M+], [Rcl] [M+] = 30).

Clears when the calculator is shut off.

**[Set] [M+] — Memory Minus (M**

−

**)**

Subtracts the displayed value from

Memory.

**[+] [–] [x] [÷] [=]**

Arithmetic operation keys.

**[Set] [–] — Change Sign (+/–)**

Toggles the sign of the displayed value

(from positive to negative or from negative to positive).

**[Set] [÷] — Reciprocal (1/x)**

Reciprocal, or 1/x function.

**[0] – [9] & [ • ]**

Digits used for keying in numbers.

**[Set] [ . ] — x**

**2**

Squares the displayed value.

**[%] — Percent**

Four function percent key.

**[Set] [%] — Square Root ( x )**

Square root function.

**4 — ElectriCalc LT**

**Mode "Set-Up" Functions**

**[Set] [x] — All-Clear (AC)**

Resets all settings and values to their default settings.

**[CU/AL] — Copper/Aluminum**

Used to toggle between copper (default) and aluminum wire types. When the wire type is revised, any calculated wire size will be re-calculated automatically.

If a wire size is entered with the wrong wire type, pressing **[CU/AL]** will change the material type without changing the size.

**Displays: Al **or **Cu**

**[Set] [1] — Single-Phase (1Ø)**

Sets calculator to single-phase mode.

**Displays: 1Ø.**

**[Set] [3] — Three-Phase (3Ø)**

Sets calculator to three-phase mode.

**Displays: 3Ø.**

**[Set] [6] — 60°C Wire Insulation**

Sets calculator to 60°C wire insulation type for wire size calculations. This is the default setting. **Displays: 60.**

**[Set] [7] — 75°C Wire Insulation**

Sets calculator to 75°C insulation type for wire size calculations. **Displays: 75.**

**User's Guide — 5**

**[Set] [9] — 90°C Wire Insulation**

Sets calculator to 90°C insulation type for wire size calculations. **Displays: 90.**

**[Set] [2] — Ambient Temperature**

Permanently enters ambient temperature for determining ampacity derived wire sizes. Ambient temperature will only change when entering a new value or by resetting the calculator (**[Set] [x]**).

Defaults to 30°C (86°F). **Amb°** will display when the ambient temperature is other than 30°C (86°F).

**Displays: Amb°.**

**[Set] [4] — Feet/Meters Toggle**

Toggles between feet and meters.

**Displays: FEET **or** MET.**

**[Set] [5] — Free Air (FrAir)**

Sets calculator into Free Air mode, which refers to NEC Table 310-17 for wire size calculations. Revises back to

Raceway mode when calculator is powered down. **Displays: FrAir.**

**[Set] [+] — °C/°F Toggle**

Toggles ambient temperature format between °C and °F. Converts displayed temperature value automatically.

**Displays**: **°C** or **°F**.

**6 — ElectriCalc LT**

**Electrical Functions**

**[kilo-] — Kilo-**

This key is used with watts, amps, volts, and volt-amps to identify "kilo-" values.

**[Set] [kilo-] — Milli-**

This key is used with other keys watts, amps, volts, and volt-amps to identify

"milli-" values.

**[Amps] — Amps**

Enters or calculates amps (using volts and VA or watts). **Displays: AMPS,**

**KAMP.**

**[Volts] — Volts**

Enters or calculates volts (using amps,

HPth, and VA or watts). Default value is

240 volts. **Displays: VOLT, KV, **or** mV.**

**[Set] [Volts] — DC Resistance**

Calculates and displays DC resistance.

**Displays: OHMS.**

**[VA] — Volt-Amps**

Enters or calculates volt-amps (using amps, volts and horsepower or watts).

**Displays: VA, KVA, **or** mVA.**

**User's Guide — 7**

**[Watts] — Watts**

Enters or calculates watts (using amps, volts, and VA or horsepower).

**Displays: WATT, KW, **or** mW.**

**[Set] [Watts] —Power Factor**

Enters or calculates power factor percentage (based on watts and VA). Defaults to 100%. Entered or calculated power factors greater than 100% will result in an error. **Displays: PF%.**

**[HPth] — Horsepower (Theoretical)**

Enters or calculates theoretical horsepower (based on Amps, VA, watts, efficiency%, PF%, and/or volts). 1.0 HPth correlates to 746 watts at 100% efficiency. **Displays: HPth.**

NOTE: This horsepower should not be confused with the motor horsepower keys used to determine motor load.

**[Set] [HPth] — Efficiency**

**Enters or calculates the percent ratio between real power (watts) and theoretical horsepower. Default: 100%. Entered or calculated efficiencies greater than 100% will result in an error. Dis- plays: EFF%.**

**8 — ElectriCalc LT**

**Ampacity Tables**

The ElectriCalc LT uses NEC Table

310-16 (310-17 for Free Air) to find wire sizes and ampacity ratings of wires. The calculator uses the following data to calculate wire size: 1) insulation temperature rating (60°C, 75°C and 90°C),

2) wire material (copper or aluminum), and 3) ambient temperature. Only standard AWG wire sizes are used by the

ElectriCalc LT.

**NOTE:** 1/0, 2/0, 3/0 and 4/0 wires are entered using the [0] key (i.e., 0, 00, 000 and 0000).

**[WireSz] — Wire Size/Ampacity**

Enters or calculates wire size based on ampacity and voltage drop, if a voltage drop length has been entered.

♦

First Press

If a wire length has been entered, the first press will show the larger of the ampacity or voltage drop derived wire size. The calculator will use the larger value when calculations require a wire size. If no voltage drop length has been entered, the calculator will display the calculated ampacity rated wire size.

**User's Guide — 9**

♦

Second Press

If a wire length has been entered, the second press displays the smaller of the two wire sizes. If not solving for voltage drop wire size, then displays the maximum ampacity.

♦

Third Press

If a wire length has been entered, displays the minimum wire ampacity rating.

**[Set] [WireSz] — 125% Ampacity**

Operates same as [WireSz], except that a factor of 125% is applied to the amperage.

**[ParSz] — Parallel Size**

Used to find the size of parallel conductors using amperage and an entered quantity of wires. Parallel wire size computations smaller than 1/0 are displayed as “nonE” as the NEC does not allow parallel wire runs smaller than 1/0.

**NOTE**: No adjustments are made for deration

♦

.First Press

When preceded by a number, calculates the applicable wire size for that quantity of wires in parallel.

**Displays: PAR WIRE SIZE**.

♦

Second Press

**10 — ElectriCalc LT**

Displays the maximum adjusted ampacity of the calculated parallel wire size. **Displays: WIRE A.**

**NOTE: **Some areas may not allow paralleling conductors. Users must know the jurisdiction requirements for their area.

**[Set] [ParSz] — Derated Wire Size**

Used to calculate derated wire sizes and allowable ampacity based on the entered quantity of wires, NEC Table

310-16 and NEC Table 310-15(b)(2)(a).

Derated wire sizes are not calculated when there are less than 4 wires, or when the unit is in Free Air mode.

♦

First Press

Calculates the derated wire size, if you have entered the number of wires, for example, 4 [Set] [ParSz]).

**Displays: D/R WIRE SIZE**

♦

Second Press

Displays the maximum adjusted ampacity of the derated wire size.

**Displays: D/R WIRE A**

♦

Third Press

Displays the derated adjustment factor per the NEC Table 310-15(b)(2)(a).

**Displays: ADJ %**

**User's Guide — 11**

**Voltage Drop Solutions**

The ElectriCalc LT will calculate maximum lengths, minimum wire sizes or actual voltage drops given the other two values. Voltage drop solutions are based on the DC resistance values found in NEC Chapter 9, Table 8.

**NOTE**: Voltage drop solutions may vary slightly from actual AC circuit values as factors such as inductive reactance, skin effect, raceway material, etc., are not considered

**[VD%] — Percent Voltage Drop**

Used to enter or calculate voltage drop.

The default voltage drop is 3%. If wire size or wire length values are not available, “nonE” will display since the voltage drop cannot be found.

♦

First Press

Enters a maximum allowable voltage drop percentage **(Displays: V DROP**

**%)** or calculates actual voltage drop

**Displays: V DROP**

♦

Second Press

Calculates actual percent voltage drop.

**Displays: V DROP %**

**12 — ElectriCalc LT**

**[Length] — Length**

Enters or calculates the maximum length of run for voltage drop computation. **Displays: FEET **or** MET**

**[Set] [Length] — Wire Resistance**

Displays the wire resistance per 1,000 feet of the wire size in [WireSz] based on NEC Chapter 9, Table 8.

**Displays: OHMS WIRE**

**User's Guide — 13**

**Ground Function Keys**

**[Grnd] — Ground**

An output-only key used to find the grounding electrode conductor size for

AC systems based on NEC Table

250-66 and an entered or calculated service-entrance conductor (largest size). Only actual wire sizes are considered valid entries.

♦

First Press

Calculates the copper grounding electrode conductor size if you have entered a valid wire size.

**Displays: GRND CU WIRE SIZE**

♦

Second Press

Displays the aluminum grounding electrode conductor size.

**Displays: GRND AL WIRE SIZE**

♦

Third Press

Displays the circular mil area used to calculate the grounding electrode conductor size. **Displays: CMIL WIRE**

**14 — ElectriCalc LT**

**[Set] [Grnd] — Equipment Ground**

**(EqGrnd)**

This function uses NEC Table 250-122 to compute the minimum equipment grounding conductor size, given an entered amperage rating or setting for a over-current device up line (i.e., 300

[Set] [Grnd]).

**NOTE**: This function deviates from the

NEC Table 250-122 for Amp values of

4001 or more. The AL conductor sizes given in the Table (1200 MCM AL) are not among those listed in Table 310-

16/17, which is the table the calculator uses to calculate wire size. In these cases, the calculator gives a slightly larger 1250 MCM AL as the appropriate

Equipment Ground wire size.

♦

First Press

Displays the copper grounding conductor size for the entered amp rating.

**Displays: EQPG WIRE SIZE CU**

♦

Second Press

Displays the aluminum grounding conductor size.

**Displays: EQPG WIRE SIZE AL**

**User's Guide — 15**

**Default Settings**

When you first receive your calculator, it is pre-set to the default settings listed below. You can always return your calculator to these default values with an

All-Clear** ([Set] [x])**.

**Ambient Temperature 30°C**

**Insulation Rating**

**Material**

**Phase**

**60°C**

**Copper (Cu)**

**3Ø**

**Volts**

**Efficiency**

**Power Factor**

**240 V**

**100%**

**100%**

**Length Units Feet**

**Voltage Drop Percent 3%**

**Wire Environment**

**(vs Free Air)**

**Raceway**

**16 — ElectriCalc LT**

**Basic Math Operations**

This calculator uses standard chaining logic, which simply means that you enter your first value, the operator (+, –, x, ÷), the second value and then the equals sign (=).

A.

3 [+] 2 [=] 5

B.

3 [–] 2 [=] 1

C.

3 [x] 6

D.

3 [÷] 1.5

**Percent Calculations**

The percent key** [%]** can be used for finding a given percentage of a number or for working add-on, discount or division percentage calculations.

355 [x] 15 [%] 53.25

250 [+] 6.5 [%] 266.25

25 [–] 5 [%]

100 [÷] 50 [%]

23.75

200.

The percent key also allows you to change percentages to decimals (e.g.,

25 [%] 0.25).

**User's Guide — 17**

**Memory Functions**

Whenever the **[M+] **key is pressed, the displayed value will be added to memory. Other memory functions:

**Function Keystrokes**

Subtract from memory

Recall total in memory

Display & clear memory

**[Set] [M+]**

**[Rcl] [M+]**

**[Rcl] [Rcl]**

**Clear memory, no display [Set] [Rcl]**

**Replace memory with displayed value [Set] [Rcl] [M+]**

The memory is semi-permanent; it will be cleared when you:

1) turn off the calculator;

2) press **[Rcl] [Rcl]**;

3) press **[Set] [Rcl];**

4) press **[Set] [x]** (all clear).

**How To Use Memory Functions:**

**Steps Keystrokes Display**

Add to M+

Add to M+

355 [M+]

255 [M+]

Recall total M+ [Rcl] [M+]

Sub. from M+ 745 [Set] [M+]

Recall & clear [Rcl] [Rcl]

355.

255.

610.

745.

– 135

**18 — ElectriCalc LT**

**Kerchoff’s Law**

The ElectriCalc LT utilizes Kerchoff’s

Law in finding volts, amps, volt-amps, watts, horsepower (theoretical), efficiency and power factor.

**Finding Voltage**

Find the voltage supply to a singlephase load drawing 14,605 volt-amps and 115 amps.

**Steps Keystrokes Display**

Clear calculator [On/C] [On/C]

Set to 1-phase [Set] 1

0.

1 PH

Enter volt-amps 14605 [VA]

Enter amps 115 [Amps]

14,605. VA

115. AMPS

Solve for volts [Volts] 127. VOLT

**Finding Amps**

What is the current (amps) for a load drawing 8,250 volt-amps on a 240 volt, three-phase circuit?

**Steps Keystrokes Display**

Clear calculator [On/C] [On/C]

Set to 3-phase [Set] 3

Enter volt-amps 8250 [VA]

Enter volts 240 [Volts]

0.

3 PH

8250. VA

240. VOLT

Solve for amps [Amps] 19.846416 AMPS

**User's Guide — 19**

**Finding Current Load**

A building with 120/240 volt 1Ø service has the following loads:

Range = 7,800 VA

Heating = 15,100 VA

Dryer = 5,100 VA

Fixed Appliances = 8,900 VA

General Lighting = 6,470 VA

What is the service load (amps) of the circuit supplying this building?

**Steps Keystrokes Display**

Clear calculator [On/C] [On/C]

Set to 1-phase [Set] 1

Add VA loads: 7,800 +

15,100 +

0.

1 PH

5,100 +

8,900 +

Enter as VA

Enter volts

6,470 [=]

[VA]

240 [Volts]

43,370

43,370. VA

240. VOLT

Solve for amps [Amps] 180.70833 AMPS

**20 — ElectriCalc LT**

**Finding Amps from Kilowatts**

What is the amperage for a 75 kW load connected in a 120/208 volt, 3Ø circuit?

**Steps Keystrokes Display**

Clear calculator [On/C] [On/C] 0.

Set to 3-phase [Set] 3 3 PH

Enter kilowatts 75 [kilo-] [Watts] 75. KW

Enter volts 208 [Volts] 208. VOLT

Solve for amps [Amps] 208.17918 AMPS

**Finding Volt-Amps**

What is the VA rating for a 120 volt, 22 amp, 1Ø circuit? What is the kVA rating?

**Steps Keystrokes Display**

Clear calculator [On/C] [On/C]

Set to 1-phase [Set] 1

Enter volts

Enter amps

120 [Volts]

22 [Amps]

Solve volt-amps [VA]

Solve for kVA [kilo-] [VA]

0.

1 PH

120. VOLT

22. AMPS

2,640. VA

2.64 KVA

**User's Guide — 21**

**Finding kVA Rating**

What is the kVA rating for a 120/208 volt, three-phase 65 amp transformer?

**Steps Keystrokes Display**

Reset calculator [Set] [x] 0.

Enter volts

Enter amps

208 [Volts]

65 [Amps]

208. VOLT

65. AMPS

Solve for kVA [kilo-] [VA] 23.417327 KVA

**Finding Wattage**

A 120 volt single-phase 45 amp electrical motor has an 87% power factor.

What is its wattage?

**Steps Keystrokes Display**

Clear calculator [On/C] [On/C]

Set to 1-phase [Set] 1

0.

1 PH

Enter volts 120 [Volts] 120. VOLT

Set power fact % 87 [Set] [Watts] 87 PF%

Enter amps 45 [Amps]

Solve for watts [Watts]

45. AMPS

4,698. WATT

**22 — ElectriCalc LT**

**Finding kW Rating**

What’s the kW rating for a 90 amp, 208 volt, three-phase broiler with 100% power factor?

**Steps Keystrokes Display**

Clear calculator [On/C] [On/C]

Set to 3-phase [Set] 3

0.

3 PH

Set power factor 100 [Set] [Watts] 100 PF%

Enter amps

Enter volts

Solve for kW

90 [Amps]

208 [Volts]

90. AMPS

208. VOLT

[kilo-] [Watts]32.423991 KW

**User's Guide — 23**

**Ampacity Wire Sizing**

The required wire size of a service conductor can be determined based on the specified electrical requirements and the [WireSz] key. The wire size is automatically recalculated whenever the wire insulation (temperature) ratings or wire material (copper or aluminum) types are revised. Wire sizing is based on the requirements defined in NEC

Tables 310-16 and 310-17.

**Wire Sizing Based on Insulation Rating**

Wiring is being installed in a 240 volt, single-phase system rated at 30 kVA.

What is the wire size needed if you use

60°C copper wire?

**Steps Keystrokes Display**

Clear calculator [On/C] [On/C] 0.

Set to 1-phase [Set] 1

Set to 60

Û&

[Set] 6

Enter kVA 30 [kilo-] [VA]

1 PH

1Ø 60 Cu 1 PH

30. KVA

Enter volts

Find amps

240 [Volts]

[Amps]

Find CU wire size [WireSz]

240. VOLT

125. AMPS

0 CU

AWG WIRE SIZE

**24 — ElectriCalc LT**

**Re-sizing Wire Based on**

**Different Insulation Ratings**

What wire size is required for a 75°C copper branch circuit carrying a load of

260 amps? What would the wire size be if 90°C copper is used?

**Steps Keystrokes Display**

Reset calculator [Set] [x] 0.

Set to 75°C [Set] 7 3Ø 75 Cu 0.

Enter amps 260 [Amps] 260. AMPS

Find wire size [WireSz] 300 CU

Change to 90

Û

[Set] 9

AWG WIRE SIZE

0000 CU

AWG WIRE SIZE

**User's Guide — 25**

**Wire Sizing Based on Ambient Temperature**

Find the 90°C aluminum wire size needed to connect a 47,700 volt-amp load to a 240 volt, single-phase source.

**Steps Keystrokes Display**

Clear calculator [On/C] [On/C]

Set to 1-phase [Set] 1

0.

1 PH

Set to 90°C

Set to alum.

[Set] 9 1 Ø 90 Cu 1 PH

[CU/AL] 1 Ø 90 Al 1 PH

Enter volt-amps 47700 [VA]

Enter volts 240 [Volts]

47,700. VA

240. VOLT

Find amps [Amps]

Find wire size [WireSz]

198.75 AMPS

0000 AL

AWG WIRE SIZE

What is the adjusted wire size, if the ambient temperature rating is changed from the default 30°C to 40°C?

Change ambient

temperature

Find adjusted

wire size

40 [Set] [2]

[WireSz]

AMB° 40 Û&

250 AL

AWG WIRE SIZE

**NOTE**: Ambient temperature will remain at 40°C unless you change it or perform an ALL CLEAR

*([Set] [x]).*

Reset amb. temp 30 [Set] [2] AMB° 30 Û&

**26 — ElectriCalc LT**

**Wire Sizing Based on**

**Material Type**

Find the wire size for a 75°C copper wire carrying a 3Ø load of 265 amps.

What is the equivalent aluminum wire size?

**Steps Keystrokes Display**

Reset calculator [Set] [x]

Set to 75°C [Set] 7

0.

3Ø 75 Cu 0.

Enter amps 265 [Amps] 265. AMPS

Find wire size [WireSz] 300 CU

Change to alum. [CU/AL]

AWG WIRE SIZE

400 AL

AWG WIRE SIZE

**User's Guide — 27**

**Sizing Parallel Conductors**

What size 60°C insulated copper wire is required for a single conductor carrying a 500 amp load in a Free Air environment (30°C amb. temp.)? What size for

2 parallel conductors? For 3 conductors?

**Steps Keystrokes Display**

Reset calculator [Set] [x] 0.

Set free air mode [Set] 5 3Ø 60 FrAir Cu 0.

Enter amps 500 [Amps] 500. AMPS

Find 1 wire size [WireSz] 500 CU

Find 2 wire size

Find 3 wire size

2 [ParSz]

3 [ParSz]

AWG WIRE SIZE

000 CU

PAR WIRE SIZE

0 CU

PAR WIRE SIZE

NOTE: Parallel wire sizes smaller than

1/0 will be displayed as nonE.

**28 — ElectriCalc LT**

**Finding Derated Wire Size**

What is the derated wire size required for nine 75°C copper wires, each carrying a maximum load of 65 amps?

**Steps Keystrokes Display**

Reset calculator [Set] [x]

Set to 75°C [Set] 7

Enter amps 65 [Amps]

Find normal

wire size [WireSz]

0.

3Ø 75 Cu 0.

65. AMPS

6 CU

AWG WIRE SIZE

Find derated

wire size 9 [Set] [ParSz] 3 CU

D/R WIRE SIZE

**User's Guide — 29**

**Sizing Temperature-Adjusted**

**Derated Wires**

A circuit was built with 90°C aluminum wire connecting a 47,650 volt-amp load to a 240 volt, single-phase source. Ambient temperature is 50°C. What is the derated wire size required if eight current-carrying THHN wires were installed in the raceway?

**Steps Keystrokes Display**

Reset calculator [Set] [x]

Set to 1-phase [Set] 1

0.

1 PH

Set to 90°C [Set] 9 1Ø 90 Cu 1 PH

Toggle to alum.

[CU/AL] 1Ø 90 Al 1 PH

Enter volt-amps 47650 [VA] 47,650. VA

Enter volts 240 [Volts] 240. VOLT

Set to 50°C amb 50 [Set] [2] AMB° 50

Û &

Find adjst wire sz. [WireSz] 300 AL

Find derated

AWG WIRE SIZE

8 [Set] [ParSz] 500 AL

wire size D/R WIRE SIZE

**NOTE:** Ambient temperature should be changed back to 30°C to avoid conflicts in answers through out the rest of this manual.

Reset to 30°C 30 [Set] [2] AMB° 30

Û &

**30 — ElectriCalc LT**

**Voltage Drop**

The reduction in voltage between the power source and the load can be determined by entering the phase, volts, amps, wire material, voltage drop wire size and length of run. The calculator determines resistance and then the voltage reduction. Voltage drop can be displayed as volts dropped, or as a percent reduction of potential load.

This calculator also finds voltage drop wire size once you have entered or calculated the phase, volts, amps, length, wire type, and allowable VD percentage. It will solve for the distance

([Length]) once you have entered or calculated the phase, volts, amps, wire type, voltage drop wire size, and allowable VD percentage. The ElectriCalc LT uses resistance values found in NEC

Table 8 to determine voltage drop.

**NOTE**: Voltage drop solutions may vary slightly from actual AC circuit measurements as the calculator does not incorporate factors such as inductive reactance, skin effect, raceway material, etc.

In most situations, the DC Voltage Drop calculation is sufficient to meet safety standards.

**User's Guide — 31**

**IMPORTANT NOTE ON**

**VOLTAGE DROP CALCULATIONS**

The ElectriCalc LT calculates voltage drop and wire size using DC resistance values as defined by the 1999 NEC. To find the voltage drop for a specific wire size, you must first enter amps (and the other required variables), then enter the specific wire size. Otherwise, if amps are entered last, the calculator will recalculate the wire size to match the ‘99

NEC Ampacity Table requirements.

**Finding Single-Phase**

**Voltage Drop**

You are installing 175 feet of 75°C, 8

THW branch circuit copper conductors to supply an 11-amp load on a 208-volt

1Ø system. What is the source voltage drop at the load? What is the percentage?

**Steps Keystrokes Display**

Reset calculator [Set] [x]

Set to 1-phase [Set] 1

Set to 75°C

Enter amps

Enter volts

[Set] 7

11 [Amps]

208 [Volts]

Enter length

*(Cont’d)*

0.

1 PH

1Ø 75 Cu 1 PH

11. AMPS

208. VOLT

175 [Length] 175. FEET

**32 — ElectriCalc LT**

**Steps Keystrokes Display**

Enter wire size 8 [WireSz] 8 CU

AWG WIRE SIZE

Solve volt. drop [VD%]

Solve % v.drop

[VD%]

3.0 DROP V

1.4 DROP V %

**Finding Three-Phase**

**Voltage Drop**

A 20-amp three-phase load is being fed by a 230-volt source located 150 feet away. The installation specifications require 75°C #10 THW stranded copper conductor. What is the voltage drop on this branch circuit?

**Steps Keystrokes Display**

Reset calculator [Set] [x] 0.

Set to 75°C

Enter amps

[Set] 7

20 [Amps]

3Ø 75 Cu 0.

20. AMPS

Enter volts 230 [Volts] 230. VOLT

Enter length(feet) 150 [Length] 150. FEET

Enter VD wire size10 [WireSz] 10 CU

AWG WIRE SIZE

Find VD

Find VD%

[VD%]

[VD%]

6.4 DROP V

2.8 DROP V %

**User's Guide — 33**

**Finding Voltage Drop Wire Size**

A 20-amp single-phase 208-volt load will be located 175 feet away from the source. Assuming a 3% allowable voltage drop, what is the size of 75°C conductor required for this branch circuit?

**Steps Keystrokes Display**

Reset calculator [Set] [x]

Set to 75°C [Set] 7

Set to single ph.

[Set] 1

Enter amps 20 [Amps]

0.

3Ø 75 Cu 0.

1 PH

20. AMPS

Enter volts 208 [Volts] 208. VOLT

Enter distance 175 [Length] 175. FEET

Enter allow. VD% 3 [VD%] 3 DROP V %

Find wire size [WireSz] 8 CU

AWG WIRE SIZE

Find actual

voltage drop [VD%]

Find % v.drop

[VD%]

5.4 DROP V

2.6 DROP V %

**34 — ElectriCalc LT**

**Finding Voltage Drop Distance**

How far from a single-phase 240-volt source can you install a 15 amp load using 60°C #10 Al branch circuit conductors? Assume a 3% allowable voltage drop.

**Steps Keystrokes Display**

Reset calculator [Set] [x]

Set to single ph.

[Set] 1

0.

1 PH

Set to aluminum [CU/AL] 1Ø 60 Al 1 PH

Enter amps 15 [Amps] 15. AMPS

Enter volts 240 [Volts]

Enter wire size 10 [WireSz]

240. VOLT

10. AL

AWG WIRE SIZE

Enter 3% VD

Find distance

3 [VD%] 3. DROP V %

[Length] 123.77387 FEET

Find actual

voltage drop [VD%]

Find % v.drop

[VD%]

7.2 DROP V

3.0 DROP V

**NOTE**: The calculator automatically makes adjustments for resistance using

NEC Chap 9, Table 8, if the insulation type is other than 75°C.

**User's Guide — 35**

**Finding Voltage Drop**

**Resistance**

What is the resistance of 85 feet of #2

90°C copper conductor?

**Steps Keystrokes Display**

Reset calculator [Set] [x]

Set to 90°C mode [Set] 9

0.

3Ø 90 Cu 0.

Enter wire size 2 [WireSz] 2 CU

AWG WIRE SIZE

Find resistance [Set] [Length] 0.2033993

OHMS WIRE

Find 85 ft resist* [÷] 1000 [x] 85 [=] 0.0172889

***NOTE**: Given resistance per 1000 feet, divide by 1000 to get a per foot resistance, then multiply by 85.

**Finding DC Resistance**

What is the equivalent resistance of a

12 volt DC circuit pulling 5 amps?

**Steps Keystrokes Display**

Reset calculator [Set] [x]

Enter voltage

Enter amps

12 [Volts]

5 [Amps]

Find resistance [Set] [Volts]

0.

12 VOLT

5. AMPS

2.4 OHMS

**36 — ElectriCalc LT**

**Ground Conductor Wire Size**

You can use single or multiple service entrance conductor(s) to find the grounding electrode conductor for AC systems. When using multiple conductors, the ElectriCalc LT uses the equivalent circular mils to find the grounding electrode conductor (based on NEC Table 250-66).

Find the grounding electrode conductor wire size required when 2/0 is the largest 3-phase 75°C copper serviceentrance conductor being used. What is the equivalent aluminum size? What is the equivalent circular mils?

**Steps Keystrokes Display**

Reset calculator [Set] [x]

Set cond. temp.

[Set] 7

0.

3Ø 75 Cu 0.

Enter wire size 00 [WireSz] 00 CU

AWG WIRE SIZE

Find grnd wire sz [Grnd] 4 CU

GRND WIRE SIZE

Find alum size [Grnd]

Find circular mils [Grnd]

2 AL

GRND WIRE SIZE

133,100.

CMIL WIRE

**User's Guide — 37**

**Equipment Grounding**

**Conductor Wire Size**

The [Set] [Grnd] keystroke can be used to find the grounding conductor size for raceways and “over-current devices in circuit ahead” equipment. The calculator uses the displayed amperage value to solve for the equipment grounding conductor based on NEC Table

250-122.

Find the equipment grounding conductor size required when the circuitbreaker is rated at 45 amps and 90° copper is being used in the installation.

What is the equivalent aluminum size?

**Steps Keystrokes Display**

Reset calculator [Set] [x]

Set cond. temp.

[Set] 9

Enter amp rating 45 [Amps]

Find equip. grnd.

wire size [Set] [Grnd]

0.

3Ø 90 Cu 0.

45. AMPS

10 CU

EQPG WIRE SIZE

Find alum size [Grnd] 8 AL

EQPG WIRE SIZE

**38 — ElectriCalc LT**

**Error Codes**

The error codes for the ElectriCalc LT are listed below (Note: To clear an error, simply press any key):

**Error Description**

1 Display register overflow

*(Answer too large to fit display)*

2 Invalid or out-of-scale entry

3 PF or EFF calculated above 100%

5 Unable to calculate VDWire Size

*(Amps/Length too high)*

9 Entered or calculated more than 15 different wires sizes

11 Temperature setting out of range for wire computation.

**1999 NEC References**

**Table 250-66**

**Table 250-122**

**Table 310-15(b)(2)(a)**

**Table 310-16**

**Table 310-17**

**Chapter 9, Tables 1, 4, 5 and 8**

**Appendix C**

**User's Guide — 39**

**Battery Information**

The calculator is powered by a single 3-

Volt Lithium CR-2032 battery. This should last upwards of 800 hours of actual use (1 year plus for most people).

If the display becomes very dim or erratic, replace the battery.

**NOTE: **Please use caution when disposing of your old batteries as they contain hazardous chemicals.

**Settings**

**Permanent Values/Settings**

Values and settings maintained in permanent memory can only be changed

(1) by pressing **[Set] [x]** (resets calculator to default settings), or (2) by changing each one or all of these settings. The following are permanent values:

**(1) Selectable (60°C/75°C/90°C) insulation ratings and CU/AL wire type ratings**

**(2) Phase setting (1Ø/3Ø)**

*(3*) The entered values for volts, voltage drop %, power factor % and efficiency %

*(3*) The entered values for volts, voltage drop %, power factor % and efficiency %

**40 — ElectriCalc LT**

**Semi-Permanent Values**

The following semi-permanent values are cleared to default settings when the calculator is shut off:

**(1) Independent User Memory**

**(2) Free Air mode**

**Warranty**

**Warranty Repair Service –**

**U.S.A.**

Calculated Industries, Inc. ("CII") warrants this product against defects in materials and workmanship for a period of one (1) year from the date of original consumer purchase in the U.S. If a defect exists during the warranty period,

CII at its option will either repair (using new or remanufactured parts) or replace

(with a new or remanufactured unit) the product at no charge.

THE WARRANTY WILL NOT APPLY

TO THE PRODUCT IF IT HAS BEEN

DAMAGED BY MISUSE, ALTERA-

TION, ACCIDENT, IMPROPER HAN-

DLING OR OPERATION, OR IF UN-

AUTHORIZED REPAIRS ARE AT-

TEMPTED OR MADE. SOME EXAM-

PLES OF DAMAGES NOT COVERED

BY WARRANTY INCLUDE, BUT ARE

NOT LIMITED TO, BATTERY LEAK-

AGE, BENDING, OR VISIBLE

**User's Guide — 41**

CRACKING OF THE LCD, WHICH

ARE PRESUMED TO BE DAMAGES

RESULTING FROM MISUSE OR

ABUSE.

To obtain warranty service in the U.S., ship the product postage paid to the CII

Authorized Service Provider listed on the back page of the User’s Guide.

Please provide an explanation of the service requirement, your name, address, day phone number and dated proof of purchase (typically a sales receipt). If the product is over 90 days old, include payment of $6.95 for return shipping and handling within the contiguous 48 states. (Outside the contiguous 48 states, please call CII for return shipping costs.)

A repaired or replacement product assumes the remaining warranty of the original product or 90 days, whichever is longer.

**Non-Warranty Repair Service**

**– U.S.A.**

Non-warranty repair covers service beyond the warranty period or service requested due to damage resulting from misuse or abuse.

Contact the CII Authorized Service Provider listed on the back page of the

User’s Guide to obtain current product

**42 — ElectriCalc LT**

repair information and charges. Repairs are guaranteed for 90 days.

**Repair Service**

**– Outside the U.S.A.**

Not all countries have CII Authorized

Service Providers or the same warranty and service policies. To obtain warranty or non-warranty repair service for goods purchased outside the U.S., contact the dealer through which you initially purchased the product. If you cannot reasonably have the product repaired in your area, you may contact CII to obtain current product repair information and charges, including freight and duties.

**Disclaimer**

CII MAKES NO WARRANTY OR REP-

RESENTATION, EITHER EXPRESS

OR IMPLIED, WITH RE-SPECT TO

THE PRODUCT’S QUALITY, PER-

FORMANCE, MERCHANTABILITY, OR

FITNESS FOR A PARTICULAR PUR-

POSE. AS A RESULT, THIS PROD-

UCT, INCLUDING BUT NOT LIMITED

TO, KEYSTROKE PROCEDURES,

MATHEMATICAL ACCURACY AND

PREPROGRAMMED MATERIAL, IS

SOLD "AS IS," AND YOU THE PUR-

CHASER ASSUME THE ENTIRE RISK

AS TO ITS QUALITY AND PERFORM-

ANCE.

**User's Guide — 43**

IN NO EVENT WILL CII BE LIABLE

FOR DIRECT, INDIRECT, SPECIAL,

INCIDENTAL, OR CONSEQUENTIAL

DAMAGES RESULTING FROM ANY

DEFECT IN THE PRODUCT OR ITS

DOCUMENTATION.

The warranty, disclaimer, and remedies set forth above are exclusive and replace all others, oral or written, expressed or implied. No CII dealer, agent, or employee is authorized to make any modification, extension, or addition to this warranty.

Some states do not allow the exclusion or limitation of implied warranties or liability for incidental or consequential damages, so the above limitation or exclusion may not apply to you. This warranty gives you specific rights, and you may also have other rights which vary from state to state.

**FCC Class B**

This equipment has been certified to comply with the limits for a Class B computing device, pursuant to Subpart

J of Part 15 of FCC rules.

**44 — ElectriCalc LT**

**Legal Notices**

Software copyrighted and licensed to

Calculated Industries, Inc. by Specialty

Calculator Technologies, LLC, 1999.

User’s Guide is copyrighted by Calculated Industries, Inc., 1999.

ElectriCalc LT and Calculated Industries are registered trademarks of Calculated

Industries, Inc.

**ALL RIGHTS RESERVED**

**Calculated Industries, Inc.**

**4840 Hytech Drive**

**Carson City, NV 89706 U.S.A**

**775/885-4975 • Fax: 775/885-4949**

**E-mail: [email protected]**

**http://www.calculated.com**

File: 5025-MN.DOC

**User's Guide — 45**

Designed in the

United States of America

Printed in Indonesia

**5025-MN V1.0**

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### Frequently Answers and Questions

###### What is the ElectriCalc LT?

###### What are the common NEC calculations the device can solve?

###### Does this calculator replace the National Electrical Code (NEC)?

###### How do I change the default wire insulation temperature rating?

###### How can I find the size of parallel conductors?

###### What units of measurement can the device display?

### Related manuals

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#### Table of contents

- 5 Key Definitions
- 18 Default Settings
- 19 Basic Math Operations
- 19 Percent Calculations
- 20 Memory Functions
- 21 Kerchoff’s Law
- 26 Ampacity Wire Sizing
- 33 Voltage Drop
- 41 Error Codes
- 41 1999 NEC References
- 42 Battery Information
- 42 Settings
- 43 Warranty
- 47 Legal Notices