TS 880 TRANSFER SWITCH
PM064 REV8 10/01/25 19 Thomson Technology
5.2.4. ADDITIONAL PROCEDURES
If the "Service Disconnected" pilot light is not illuminated, the service will not have
been successfully disconnected and therefore it is not safe to perform any
maintenance until the following additional procedures are performed:
DANGER!!!!
Arc Flash and Shock Hazard. Will cause severe injury or death.
Do not open equipment until ALL power sources are disconnected
This equipment must be installed and serviced only by qualified electrical
personnel utilizing safe work practices and appropriate Personal Protective
Equipment (PPE). Failure to do so may cause personal injury or death
1. On 100A-1200A molded case power switching unit type transfer switches, open
the door to the transfer switch using a suitable tool and open the door lock with
the key.
2. Visually inspect the actual position of the transfer switch mechanism as follows:
On 100A-1200A molded case power switching unit type transfer switches: If the
position of the transfer switch mechanism is clearly in the "neutral position", and
the load bus is de-energized on all phases, the service has been successfully
disconnected. Proceed to Step. 4.
• If the position of the transfer switch mechanism is not in the neutral
position or the load bus is energized, further procedures are required.
On 800A-4000A insulated case power switching unit type transfer switches,
verify both power switching devices are in the OPEN position. If both power
switching devices clearly indicate they are in the OPEN position, the service has
been successfully disconnected.
Note: If the position of the transfer switch mechanism is clearly in the "neutral
position, the "service disconnected" pilot light may not have illuminated
due to the following reasons:
a) Utility and generator supply voltages are not present (the pilot light
requires AC supply voltage to be present).
To Next Page
Loading...
Need help?
General
