Instructions

April, 2000

Supersedes Issue of

April, 1992

97-HUM

Current Sensitive Relay

Manual Reset

Class 97, 97A, & 97U

The current sensitive relay is a device that montiors motor current and protects machinery and equipment from damaging overloads by sensing either an undercurrent condition (Model

97U) or an overcurrent condition (Model 97A). This condition may be the result of a system or motor malfunction or a product jam. 120VAC is required to operate the current sensitive relay.

A normally open and closed contact is provided.

Start-up Delay, Trip Delay, and Current Trip (Undercurrent Trip on the Model 97U and Overcurrent Trip on the Model 97A) adjustments are provided to match the current sensitive relay to a specific application. An Auto/Manual Reset switch is provided along with a Fault indicator light.

Electrical Data

Supply Voltage:

Start Up Time Delay:

Trip Time Delay:

100 - 140 VAC, 60 Hz

1 - 6 seconds. Begins when motor current is above 10 % of current trip point. Output is inhibited if motor current is below 10% of current set point.

Model 97U

0.5 - 2.5 seconds

Model 97A

0.2 - 2.5 seconds

Model 97U - Undercurrent Control Styles

Catalog

Number

Current Trip

Adjust

Range

(Amps)

Maximum

Continuous

Hp Range Operating

@ 460 V Current (Amps)

97UM*0207

97UM*0416

97UM*0728

97UM*1456

2 - 7

4 - 16

7 - 28

14 - 56

3 - 7.5

5 - 15

10 - 30

20 - 60

125

140

140

140

Reset:

Fault Indicator:

Contact Rating:

Wire Termination:

Manual or automatic, user selectable

LED, on during fault

1 Form C, 2.5 amp @

250 VAC (NEMA C300)

Saddle Clamp

Wire Range: Two #12 to 18 ga.

Model 97A - Overcurrent Control Styles

Catalog

Number

Current Trip

Adjust

Range

(Amps)

Maximum

Continuous

Hp Range Operating

@ 460 V Current (Amps)

97AM*0207

97AM*0416

97AM*0728

97AM*1456

97AM*3010

2 - 7

4 - 16

7 - 28

14 - 56

30 - 100

1 - 3

3 - 7.5

5 - 15

10 - 30

30 - 75

125

140

140

140

140

* Use complete catalog number, replace * with mounting type:

F = free standing

M = mounting panel

Sense Loop Wire Size:

Operating Temperature Range: -25 vC to 60vC

Set Point Repeatability:

6 gauge maximum except

97AAF3010 2/0 gauge maximum

I2% over temperature range of 0 v to 60vC

I4% over temperature range of -25

Current Transformers (Optional) Rating

150:5

200:5

250:5

300:5

400:5 vC to 0vC

Part Number

D81509-002

D81509-003

D81509-004

D81509-005

D81509-006

The styles above can also be used on voltage systems other than 460 VAC by changing Hp range proportionally.

(For Engineering Reference Only - Rev. C)

Siemens Energy & Automation, Inc. 1000 McKee Street Batavia, Illinois 60510

Instructions 97-HUM

Page 2

April, 2000

Supersedes April, 1992

Set-Up

The current sensitive relay has three adjustments, Current Trip

(Overcurrent Trip or Undercurrent Trip), Start-up Delay and Trip

Delay.

Current Trip

The Current Trip adjustment (Undercurrent Trip, Model 97U;

Overcurrent Trip, Model 97A), is used to set the level at which the current sensitive relay will trip.

On the Model 97U unit, should the motor current fall below the value of the Undercurrent Trip adjustment for a time period which is longer than the Trip Delay setting, the current sensitive relay output will be energized. The undercurrent value should be set below the normal operating current value of the motor.

On the Model 97A unit, should the motor current rise above the value of the Overcurrent Trip adjustment for a time period which is longer than the Trip Delay setting, the current sensitive relay output will be energized. The overcurrent value should be set above the normal operating current value of the motor.

Start-up Delay

The Start-up Delay allows the motor to start without tripping the current sensitive relay. The delay is adjustable from 1 to 6 seconds. The Start-up Delay timer begins when the motor current rises above 10% of the current trip setting. When this occurs, the Start-up Delay will inhibit the energizing of the output relay for the period of time of the Start-up Delay.

Trip Delay

After the start-up delay period has ended, any overcurrent or undercurrent condition lasting longer than the setting of the Trip

Delay (0.5 to 2.5 seconds on the Model 97U and 0.2 to 2.5 seconds on the Model 97A), will cause the current sensitive relay to energize its output.

Auto/Manual Reset

An Auto/Manual Reset function is provided. With the selector switch in the Auto position, the fault light and output relay will be energized as long as the fault condition exists. When the fault clears, the fault light will go out and the output relay will deenergize. With the switch the Manual position, the fault light and relay output will remain energized after the fault is cleared.

Ma ua mode, move the Reset switch to the Auto position and then back to the Manual position. The relay output and fault light will now be in the unenergized state (as long as no fault is present).

Approximate Adjustment Levels

Siemens Energy & Automation, Inc. 1000 McKee Street Batavia, Illinois 60510

Instructions

Operation

Model 97U - Undercurrent Sensitive Relay

97-HUM

Page 3

April, 2000

Supersedes April, 1992

Model 97A - Overcurrent Sensitive Relay

Siemens Energy & Automation, Inc. 1000 McKee Street Batavia, Illinois 60510

Instructions

Wiring Diagram

Dimensions

97-HUM

Page 4

April, 2000

Supersedes April, 1992

Siemens Energy & Automation, Inc. 1000 McKee Street Batavia, Illinois 60510