Tornatech GPX User Manual

8
When the Alternate Power Source is within acceptable limits (above 90% of the nominal voltage) for a certain set
time (factory set at 3 seconds), the transfer to alternate power source is initiated.
The transfer switch will remain in the alternate power source position until the normal source is restored.
RETRANSFER TO NORMAL
Important: The transfer switch will stay in alternate position, if the motor is running, for as long as the alternate
power source is within acceptable limits. The retransfer sequence is enabled if the motor is not running.
The Retransfer to the Normal Power source starts when the voltage sensor detects restoration of the Normal Power
Source within acceptable limits. The voltage level must rise above the pre-set pickup value (90%) on all phases
before the sensor will accept the normal source.
When the normal source is accepted by the sensor, the retransfer to normal delay timer starts timing (factory set at
5 minutes). This delay can be by-passed by pressing on the count-down timer displayed on the screen (if a flashing
“X” is displayed).
This delay prevents immediate load retransfer to the normal source. The delay insures that the normal power
source has stabilized before reconnection of the Fire Pump Motor. If the normal source voltage falls below the pre-
set dropout value before the time delay expires, the timing cycle is reset to zero. If the alternate power source fails
during the timing cycle, the load is immediately retransferred to the normal source, if that source is acceptable.
The Automatic Transfer Switch is now feeding the Fire Pump Motor from the Normal Power Source again.
Upon retransfer to the normal source, the 5 minute cooling timer starts counting down, keeping the engine running
during this cool-down period. This delay can be by-passed by pressing on the count-down timer displayed on the
screen (if a flashing “X” is displayed).
After the time delay, the relay is re-activated to shut down the engine-driven generator. All circuits are reset for any
future normal source failure.
Every time the transfer switch needs to change from one power source to the other, a running motor is stopped
during the transfer to prevent instant across the line starting of an already turning motor. If the motor still needs to
run when the transfer sequence has completed (plus a factory set 2 second timer), the motor will be restarted
following its default start-up sequence.

Tornatech GPX Specifications

General

Brand	Tornatech
Model	GPX
Category	Controller
Language	English