5.0 1 4 /4 1 5 /2 13 /64 DIA. 4 MTG. HOLES Current Balance Relays Function: 60 or 87 WILMAR Protective Relays WCB Series ANSI/IEEE C37.90-1978 UL file No. E58048 TERMINAL STRIPS CSA file No. LR61158 6 - 32 SCREWS 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. PART NUMBER SELECTION Note: Dimensions in inches. Multiply values by 25.4 for dimensions in mm. PRODUCT SPECIFICATIONS PART NUMBER SELECTION Part Number WCB Series Sample Part No. WCB-120AC-1-A Line Current ..................................... Type: Three Phase, AC current, 50-400 Hz Direct or from CT. 5 amp continuously WCB = Current Balance 20 amp, 30 sec. Control Voltage ( 15%) 200 amp, 0.10 sec. 26 DC 48 DC Control Voltage ................................ See Part Number Selection 125 AC 120 AC Unbalanced Trip Point ..................... Screwdriver adjustable. Adjustment range in 230 AC accordance with ordering information. (The unbalanced 380 AC value is defined as the difference between the highest 460 AC and the lowest phase current). Trip Adjustment Range .5 = 0.1 amp to 0.5 amps Drop-Out Time Delay ....................... 0.9 to 1.3 seconds 1 = 0.2 amp to 1 amp Surge Withstand Capabiliy .............. 2 = 0.4 amp to 2 amp In compliance with C37.90B ANSI/IEEE Options: o o Operating Temperature .................... -40 C to +70 C A = two normally open contacts B = two normally closed contacts Burden .............................................. Current input: 5.0 VA, Phase Control voltage: 3.0 VA Contact Ratings ................................ One set, N.O., One set N.C. 5 amp resistive at 120 VAC or 28 VDC 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. 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) 1 3 /2 4.0 5.0