OPERATION

BE3-27T and BE3-59T ac voltage relays have two external, user

adjustable controls marked SET and DELAY. The BE3-27T/59T has

four controls: UNDER SET, OVER SET, UNDER DELAY, and

OVER DELAY. The SET control adjusts the relay trip point. An

overvoltage trip causes the relay output to energize when the

voltage rises above the SET threshold. The overvoltage SET level

is adjustable from 100 to 125% (±3%) of nominal input (Vnom

). An

undervoltage trip causes the relay output to de-energize when the

voltage decreases below the SET threshold. The undervoltage SET

level is adjustable from 75 to 100% (±3%) of nominal input. Time

delay is the amount of time that elapses after the trip point is

reached and when the output relay operates.

Setting Example: a BE3-59T relay with a nominal input rating of 240

Vac has the following settings:

• SET – 120%

• DELAY – 4 seconds

A trip occurs when the sensing voltage rises above 288 Vac and 4

seconds elapses. Reset occurs when the voltage decreases below

285.6 Vac (1% of nominal below setpoint).