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 %
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