Function:

32

Tyco Electronics / www.tycoelectronics.com / Factory Direct Technical Support: 800-253-4560, ext. 2023 (U.S., Canada, Mexico) or 805-220-2020, ext. 2023 (International)

Current Balance Relays are designed to sense un-

balanced current flow in a three phase system. The

primary application of Current Balance Relays is to

protect three phase motors against phase unbal-

ance or phase failure.

Operation:

With control voltage applied to the relay, the output

contacts will energize when the three phase currents

are balanced (including zero currents), and will be

de-energize by unbalance currents.

Current Balance Relays

PRODUCT SPECIFICATIONS

Sample Part No.

WCB-120AC-1-A

Type:

WCB = Current Balance

Control Voltage

(± 15%)

26 DC

48 DC

125 AC

120 AC

230 AC

380 AC

460 AC

Trip Adjustment Range

.5 = 0.1 amp to 0.5 amps

1 = 0.2 amp to 1 amp

2 = 0.4 amp to 2 amp

Options:

A = two normally open contacts

B = two normally closed contacts

PART NUMBER SELECTION

Notes:

1.

Remove black screw for access to the trip adjustment.

2.

Clockwise rotation of the adjustment potentiometer will raise the unbalance trip point.

3.

The output contacts are shown de-energized.

PART NUMBER SELECTION

Part Number

Line Current .....................................

Control Voltage ................................

Unbalanced Trip Point .....................

Drop-Out Time Delay .......................

Surge Withstand Capabiliy ..............

Operating Temperature ....................

Burden ..............................................

Contact Ratings ................................

WCB Series

Three Phase, AC current, 50-400 Hz Direct or from CT.

5 amp continuously

20 amp, 30 sec.

200 amp, 0.10 sec.

See Part Number Selection

Screwdriver adjustable.

Adjustment range in

accordance with ordering information. (The unbalanced

value is defined as the difference between the highest

and the lowest phase current).

0.9 to 1.3 seconds

In compliance with C37.90B ANSI/IEEE

Current input: 5.0 VA, Phase Control voltage: 3.0 VA

One set, N.O., One set N.C.

5 amp resistive at 120 VAC or 28 VDC

60 or 87

13

4 MTG. HOLES

4.0

5.0

TERMINAL STRIPS

#6 - 32 SCREWS

WILMAR™ Protective Relays – WCB Series