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1.2.3 LOAD SHED CONTROLLER
The primary function of the Load Shed Controller (LSC) is to deter-
mine when there is excess load on the generator and has the ability
to disconnect the non-essential loads connected to it. Excess load
is determined by monitoring the generator supply frequency, if the
frequency drops below 58 Hz for more than three (3) seconds,
or below 50 Hz for 1/2 second, and the generator is considered
to have excess load on it. When this happens, non-essential
customer loads are disconnected. The non-essential loads are
supplied via the load shed switch (LSS) and the LSS is actuated to
disconnect these loads.
The non-essential loads are reconnected in one of 3 ways; Utility
voltage is restored and ATS transfers all load back to the Utility
supply, manual operation of LOAD SHED RESET/TEST push-button
on the outside of the enclosure (Figure 1.2) or, automatic operation
setup on the DIP switches on the LSC.
For manual operation, set DIP switch #6 to the ON position. If
the generator output is overloaded and the non-essential loads
are disconnected, press the LOAD SHED RESET push-button to
reconnect the non-essential loads to the generator. If the overload
condition still exists the LSC will turn the non-essential loads off.
For automatic operation, the number of attempts to reconnect the
non-essential loads can be selected. The 2 choices are one-shot
or repeated. The time interval before each attempt is set on DIP
switches 1-4. For "one-shot" operation mode set DIP switch #5 to
ON. Reconnection of the non-essential loads will occur one time,
after the time set on DIP switches 1-4. If DIP switch #5 is OFF,
the LSC will attempt to reconnect the non-essential loads after the
time interval set on DIP switches 1-4. If the overload still exists or
comes back, the LSC and LSS will disconnect non-essential loads
and the timer and the attempt to reconnect non-essential loads
will be repeated.
DIP switch num-
ber
1
Selects a 5 minute reconnection time
2
Selects a 15 minute reconnection time
3
Selects a 30 minute reconnection time
4
Selects a 60 minute reconnection time
1-4 all OFF
Selects a 1 minute reconnection time
5
Selects one-shot mode
6
Selects manual reconnect only
7
Selects 50 Hz units
8
Not used
Function
Figure 1.2
1.3
TRANSFER SWITCH DATA
DECAL
A DATA DECAL is permanently affixed to the transfer switch enclo-
sure. Use this transfer switch only with the specific limits shown
on the DATA DECAL and on other decals and labels that may be
affixed to the switch. This will prevent damage to equipment and
property.
When requesting information or ordering parts for this equipment,
make sure to include all information from the DATA DECAL.
Record the Model and Serial numbers in the space provided below
for future reference.
MODEL #
SERIAL #
1.4
TRANSFER SWITCH
ENCLOSURE
The standard switch enclosure is a National Electrical
Manufacturer's Association (NEMA) 3R, UL listed. NEMA 3R type
enclosures primarily provide a degree of protection against falling
rain and sleet and is undamaged by the formation of ice on the
enclosure.
General Information
3
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