General Theory Of Operation; Automatic Sequence Of Operation; Service Entrance Automatic Transfer Switch Operation - THOMSON TS 910 Owner's Manual

5.

GENERAL THEORY OF OPERATION

5.1.

AUTOMATIC SEQUENCE OF OPERATION

Note: Time delays indicated below are factory default settings only. Refer to
manual for alternate time delay settings available on TSC 9 Controller
UTILITY POWER FAIL
GEN START
GEN WARM-UP
TRANSFER TO GEN
LOAD SHED ACTIVATE
UTILITY POWER RETURN
TRANSFER TO UTILITY
LOAD SHED RESET
GEN COOL DOWN
5.2.

SERVICE ENTRANCE AUTOMATIC TRANSFER SWITCH OPERATION

5.2.1. OVER CURRENT TRIP
Should the utility breaker trip open due to an over current condition, TSC 9 transfer
controller will initiate an engine start signal and will permit transfer of the load to the
generator supply. The utility source will be locked out and the load will remain on the
generator supply until the Utility Service Entrance breaker is manually reset.
5.2.2. SERVICE DISCONNECT PROCEDURE
To initiate a Utility Supply Service Disconnect, follow procedure shown below:
5.2.2.1.
PM140 REV 0 12/02/09
TS 910 TRANSFER SWITCH
When voltage drops on any phase of the utility supply below 70%
of rated voltage, a generator start sequence will be initiated.
The generator will start following expiry of the 3 second Gen
Start timer.
A generator warm-up period will be initiated once the generator
starts and reaches 80% rated voltage and 90% rated frequency.
The load will transfer to the generator supply following expiry of
the 10 second Gen Warm-up timer.
All non-essential loads connected to Load Shed control circuit
will be de-energized once generator transfers on load (If kW
Load Shed option is installed, refer to Section 18.16 of this
manual for further details).
When utility power is restored to above 80% rated voltage on all
phases, a utility power return sequence will be initiated.
The load will transfer from generator to utility power following
expiry of the 120 second Utility Return timer, provided both
generator and utility voltages are in-phase at time of transfer.
All non-essential loads connected to Load Shed control circuit
will be re-energized once load transfers to utility power.
The generator will automatically stop following expiry of the 2
minute Gen Cool Down timer.
TURN OFF GEN STARTING CONTROL: At the generator set,
turn it's automatic starting control to OFF position to prevent generator
8
Section 18.15 of this
Thomson Technology