ABB CM Folheto de instruções - Página 7

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current through the trip circuit to close the contacts of

the ICS. This value of current should be not greater

than the particular ICS tap setting being used. The

operation indicator target should drop freely.

The contact gap should be approximately .047"

between the bridging moving contact and the station-

ary contacts. The bridging moving contact should

touch the stationary contacts simultaneously.

7.1.3.2.

AC Indicating Contactor Switch (ACS)

Close the main relay contacts and pass sufficient ac

current through the trip circuit to close the contacts of

the ACS. This value of current should be not greater

than the particular ACS rated operating current being

used. The operation indicator target should drop

freely.

The contact gap should be approximately 3/32"

between the bridging contact and the adjustable sta-

tionary contacts. The bridging moving should touch

both stationary contacts simultaneously.

7.2. ROUTINE MAINTENANCE

All relays should be inspected periodically and the

time of operation should be checked at least once

every year or at such other time intervals as may be

dictated by experience to be suitable to the particular

application. Phantom loads should not be used in

testing induction-type relays because of the resulting

distorted current wave form which produces an error

in timing.

All contacts should be periodically cleaned. A contact

burnisher style #182A836H01 is recommended for

this purpose. The use of abrasive material for clean-

ing contacts is not recommended, because of the

danger of embedding small particles in the face of

the soft silver and thus impairing the contact.

8.0 CALIBRATION

Us the following procedure for calibrating the relay if

the relay has been taken apart for repairs or the

adjustments disturbed. This procedure should not be

used until it is apparent that the relay is not in proper

working order. (See "Acceptance Check").

8.1. MAIN UNITS

For all electrical checks refer to test diagram figure 5.

For tapped CM, put tap screw in one amp tap setting.

1. Balance Setting

a) Mechanical balance - adjust spiral spring

until moving contact is located substantially

in the center of the scale plate.

b) Electrical Balance

1. Apply two amperes on front and rear

electromagnets and adjust resistor at

rear of specific unit being tested such

that the moving contact is in balance,

i.e., moving contact is aligned per part

"a" above.

2. Apply twenty amperes on front and rear

electromagnets for approximately two

seconds and note that the moving con-

tact does not deviate from the balanced

condition more than approximately 1/4

inch.

For CM relays with adjustable magnetic plugs, only

the right-hand plug may be adjusted. At the factory,

the right-hand plug is adjusted to help obtain a bal-

anced condition of the contact at 20 amperes. The

moving contact is again checked at 2 amperes. Little

adjustment, if any, is expected to be necessary in the

field.

2. Minimum Trip Setting

The front electromagnet energized alone should

produce a disc rotation to the left while the rear

electromagnet energized alone should produce a

disc rotation to the right.

a) Apply one ampere to front electromagnet

and adjust left stationary contact until it just

makes with the moving contact. This setting

should correspond with the marking on scale

plate.

b) Apply one ampere to rear electromagnet and

adjust right stationary contact until it just

makes with the moving contact. This setting

should correspond with marking on scale

plate.

3. Operating Curve

Apply six amperes to front electromagnet and

vary current flowing through rear electromagnet.

a) The moving contact should make with the

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