Installation / Operation / Maintenance Manual
10/28/2019
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8.
TROUBLESHOOTING GUIDE
This guide is intended to assist an individual with a basic understanding of electrical circuitry to troubleshoot an
automatic transfer switch as manufactured by Lake Shore Electric Corporation. Any questions relating to the use of this
Manual should be referred to the Service Department of Lake Shore Electric Corporation, 205 Willis Street, Bedford,
Ohio 44146, Phone (440) 232-0200, Fax (440) 232-5644.
CAUTION: WHEN WORKING ON EQUIPMENT OF THIS TYPE, EXTREME DANGER FROM
ELECTRICAL HAZARDS EXITS. DO NOT ATTEMPT ANY REPAIRS OR ADJUSTMENTS TO THIS
EQUIPMENT WITHOUT TAKING EVERY PRECAUTION TO PREVENT AN ACCIDENT.
WARNING!
IN INSTALLATION AND USE OF THIS PRODUCT, COMPLY WITH THE NATIONAL ELECTRICAL CODE,
FEDERAL, STATE AND LOCAL CODES, AND ALL APPLICABLE SAFETY CODES. IN ADDITION,
TURN
OFF
POWER
AND TAKE OTHER NECESSARY PRECAUTIONS TO PREVENT PERSONAL INJURY AND
EQUIPMENT DAMAGE.
WHEN WORKING ON EQUIPMENT OF THIS TYPE, EXTREME DANGER OF ELECTROCUTION EXISTS.
THIS MAY RESULT IN INJURY OR DEATH.
DO NOT
ATTEMPT ANY REPAIRS OR ADJUSTMENTS TO
THIS EQUIPMENT WITHOUT FIRST TAKING EVERY PRECAUTION TO PREVENT ACCIDENTAL INJURIES.
The following conditions
MUST
be met before attempting to troubleshoot a molded case transfer switch:
1.
A wiring diagram for the switch must be available.
2.
Normal and Emergency voltage and frequency must be available and within the correct operating
limits.
3.
Control fuses must be in proper working order.
4.
Control circuit voltage (if transformers are used) must be 110 to 125 volts.
5.
Connections to the PFR must be correct and the relay must be adjusted to pick up on the voltage at
which the switch is operating. See voltage relay instructions on a Page 17.
6.
All timers must be turned down or considerations given to them while the tests are being conducted.
7.
If trip units are included in the switch, they must be reset if previously tripped due to an overload.
8.
All electrical connections must be tight and in accordance with the wiring diagram.
9.
All components must be free of obvious defects with the exception of normal usage.
10.
The switch must be connected to a good earth ground.
When you are satisfied that all the above conditions are met, and all accessories are either working correctly or
eliminated, the problem will be confined to:
1.
The control relays and timers
2.
The molded case switches.
3.
The adjustment of the operating mechanism.
4.
The motor and micro switches.
The troubleshooting procedures outlined here are designed to test the control circuit and the operating mechanism of the
transfer switch. It is, therefore, necessary that all factors external to the transfer switch are correct, and that all accessory
devices which are not imperative to switch operation either operate satisfactorily or be bypassed and jumped out of the
circuit.
Many of the accessory devices described below may not exist in the transfer switch being examined. The proper wiring
