Turn on variable voltage source connected at terminals 1, 2, and 3 of K111 and set for an output
voltage of 240 V ac as reflected on the voltmeter. Monitor multimeter at terminals 4 and 6 of the
relay. Multimeter should read zero ohms.
Gradually decrease voltage input into the relay by turning down the variable voltage source. The
relay should trip when voltage from the variable voltage source decreases to 166 5 V ac as
indicated on the voltmeter. Multimeter should read infinite ohms at this point, showing that the relay
contacts have changed state. Record voltmeter reading.
Turn off the variable voltage source with its output level set at the trip voltage recorded in step (b)
above. After 10 seconds, turn variable voltage source back on while timing relay trip time with a
stopwatch. Multimeter at this point should deflect to zero ohms. Relay should trip within 1 1/21
seconds as indicated by the multimeter deflecting back to infinite ohms.
If relay does not trip at specified voltage (166 i5 V ac), turn the trip voltage adjustment at upper left of the
relay clockwise or counterclockwise to either increase or decrease the undervoltage threshold level.
Repeat step (2)(b), above, and continue adjusting until the desired 166 ±5 V ac trip point is obtained.
If relay does not trip within the specified 1 1/21 seconds time delay, turn the time delay adjustment pot at
upper right of relay clockwise or counterclockwise to either increase or decrease the relay's time delay
setting. Repeat step (2)(c), above, and continue adjusting until the specified 1 1/2±1 seconds time delay is
Replace. If the specified undervoltage threshold and/or time delay period cannot be attained through the
relay adjustment pots, replace the undervoltage relay.
Install. See Figure 5-9.
Install undervoltage relay K1 (64) and secure with screw and captive washer assemblies (62).
Make wiring connections as tagged and discard tags.
5-36. OVERCURRENT RELAY K114 (65, Figure 5-9).
Inspect for overall cleanliness and damage.
Ensure that plexiglass faceplate is clean, intact, and securely fastened by the three captive screws.
Ensure that all electrical wiring and mounting connections are secure.
Remove. See Figure 5-9.
Tag and disconnect wiring from overcurrent relay K114 (65).
Remove four screws (66) from rear of panel and carefully slide overcurrent relay K114 (65) free from front
Test. See Figure 5-30.
Preparation for bench test.
Remove overcurrent relay in accordance with step b, above.
Obtain a 24 V dc power source, a 24 V, 0-15 ampere ac power source, a dc voltmeter, and an ac
Connect the positive lead of the 24 V dc power source to terminal 7 of relay K114 and the negative
lead to terminal 8 of relay K114. Install the dc voltmeter across terminal 12 of relay K114 and the
negative lead of the 24 V dc power source. Connect the 24 V, 0-15 ampere ac power source across
terminals 5 and 6 of relay K114. Install the ac ammeter in series between the 24 V, 0-15 ampere ac
power source and terminal 6 of relay K114.