ABB CA-26 Manual de instruções - Página 11

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3. Percentage Slope Characteristic

Connect the relay per the test circuit of Figure

11. Pass 20 amperes for the CA-16 and 14

amperes for the CA-26 relay into terminals 9 and

19 of the relay. Adjust the plug (when used) in

the operating electromagnet until the contacts

just close with the following currents into the

operating circuit of the relays.

1. CA-16

2. CA-26

4. Time Curve

Place the permanent magnet on the relay and

apply 20 amperes to terminals 12 and 13 of the

relay. Adjust the keeper of the permanent mag-

net until the contacts just close in the following

times.

1. CA-16

2. CA-26

These times should be the average of 5 read-

ings.

5. Indicating Contactor Switch (ICS)

Close the main relay contacts and pass sufficient

dc current through the trip circuit to close the

contacts of the ICS. This value of current should

not be greater than the particular ICS tap setting

being used. The operation indicator target should

drop freely.

6. Indicating Instantaneous Trip Unit (IIT)

The core screw must be adjusted to the value of

pick-up current desired. It is recommended that

the IIT be set to pick-up at a value of current that

is equal to the maximum rms symmetrical exter-

nal fault current to the relay.

Courtesy of NationalSwitchgear.com

29.4 to 34 amperes

36 to 40 amperes

52 ± 5% Milliseconds

72 ± 5% Milliseconds

7. Sensitive Fault Detector

Loosen the lock nut at the top of the element and

run the core screw down until it is flush with the

top of the lock nut. Back off the Micarta disc by

loosening the two lock nuts. Apply 0.15 amperes

to terminals 14 and 15. Operate the moving ele-

ment by hand and allow the current to hold the

moving contact disc against the stationary con-

tacts. Now, screw up the core screw slowly. This

causes the plunger to move up, compressing the

spring until a point of maximum deflection is

reached. Further upward motion will cause the

plunger to drop part way out of the coil, thus

diminishing the spring pressure on the contacts.

By thus adjusting the core screw up or down the

maximum spring deflection for this value of cur-

rent may be found. Then lock the core screw in

place. Next, adjust the de-energized position of

the plunger by raising the Micarta disc until the

plunger just picks up electrically at the 0.15

ampere value.

8.1.

Electrical Checkpoints

Figures 12 and 13 will aid in trouble shooting either

the CA-16 or the CA-26 relays. These curves show

the operating current to trip the relay for different

restraint current for one restraint element as well as

for six restraint elements connected in series.

9. RENEWAL PARTS

Repair work can be done most satisfactorily at the

factory. However, interchangeable parts can be fur-

nished to customers who are equipped for doing

repair work. When ordering parts, always give the

complete nameplate data.

41-337.3L