Caution, Warning, Maintenance – Howard SVR1 Regulator User Manual

Page 13

background image


SVR-1 Step Voltage Regulator

Document No. 2.4.114

Revision: 03

Issued: March, 2012


Copyright © 2012 Howard Industries, Inc.



Periodic operational checks should be performed to verify

proper operation of the control unit, the tap changer

mechanism, and the HI-AMP™ limiters. These checks

can be made while the regulator is in service. Output

voltage should be monitored during the procedure using

a voltmeter connected to the control unit’s test terminals.

The control unit manual should be referenced for further


The following procedure should be followed to check

operation of the control unit, the tap changer mechanism,

and the HI-AMP™ limiters.
1. Referring to control panel indicators, make sure

the regulator is “IN-BAND” and that line drop

compensation is set to zero (Return line drop

compensation to the proper setting after completing

the checklist.).

2. Verify that the voltmeter indicates a voltage within

one-half of the bandwidth tolerance.

3. Place the AUTO/MANUAL switch in the “MANUAL”


4. Using the RAISE/LOWER switch run the tap changer

several steps in either direction, until control panel

indicates an out-of-band condition.

5. Return the AUTO/MANUAL switch to the “AUTO”

position. After a time delay, the control will

automatically return the regulator to an in-band


6. Repeat steps 3 through 5, but in the opposite


7. Check operation of the HI-AMP™ limit switches

(located on the either side control position indicator)

by attempting to run the regulator beyond the limits

set by the switches. The limit switches should stop

tap changer operation at the corresponding tap



SVR-1 step voltage regulators are designed for long

life and trouble-free operation. Periodic inspection and

maintenance will prolong life and minimize the likelihood

of service interruptions. Proper operation can be checked

without removing the regulator from service. Follow

the procedures in this section to perform in-service

inspection and maintenance.

The operational life of a regulator will depend somewhat

on the application and environment; hence, the

frequency and scope of maintenance should be tailored

to a regulators specific situation. Regulators subjected

to higher loads and/or more frequent tap changer

operations should be inspected more frequently than

regulators exposed to lighter duty.

In certain situations it might be advisable to periodically

remove a regulator from service for thorough testing and

internal inspection. In addition, anytime an operational

regulator is removed from service for any reason, the

opportunity should be used for testing and a thorough

inspection, following the procedure in the pre-installation

checklist (page 5) at a minimum.

The procedures outlined below are intended to verify

proper operation of the control unit, tap changer

mechanism, HI-AMP™ limiters, and cooling fans (if

present), and to check for tap changer contact wear and

the condition of the insulating fluid. Other checks may be

advisable for certain regulators, particularly those serving

special applications or operating in severe environments.

The user should contact Howard Industries Regulator

Division for additional information.


Operation of the regulator to extreme tap positions

can produce a line voltage that is above or below the

desired operating limit of the load, causing property



These maintenance instructions should be followed

to ensure proper and safe regulator operation.

Tampering or maintenance by unqualified personnel

can degrade operational performance and can cause

unsafe conditions that can cause death, serious

personal injury, or property damage.