Avtron 1035409, Manual

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Description
Avtron Outdoor Load Bank • Part Number K875A 1035409
2-1
SECTION II
DESCRIPTION
The Avtron Model K875A 1035409 Resistive Load Bank is a vertical airflow unit designed to
provide a balanced resistive load of unity power factor, at a specified 3-phase voltage. The total
load capability of the K875A Load Bank is 600 kW at 480 VAC, 3-phase, 60 Hz. Load steps are
150, 150, 150, and 150 kW. Using the toggle switches on the control panel, any combination of the
available load steps may be selected to achieve a desired load.
This Load Bank provides a pilot relay interface (120 VAC) for complete control of the Load Bank
including blower, load steps, and safety control circuits. It is the customer’s responsibility to remove
all the load steps if the blower is turned off or an airfail/overtemperature condition is detected.
The K875A 1035409 Load Bank contains a fan with a 3-phase, 480 VAC, 60 Hz, 10 H.P.
1800 RPM fan motor which provides the necessary cooling air for the load elements. The fan motor
is controlled by a motor starter contactor. Overcurrent protection is provided for the motor by three
fuses and an overload relay. The overload relay does not have an automatic reset provision and must
be reset manually. The fan’s free air delivery is nominally 20,000 CFM.
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C A U T I O N
This Load Bank should never be used without the fan motor
operating. Inadequate cooling airflow will result in resistor elements
causing overheating and a definite fire hazard.
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An airflow switch is provided to monitor the flow of cooling air. This differential pressure switch is
electrically interlocked with the load application controls to prevent load application if the fan is not
working properly (AIR FAILURE light comes on).
An overtemperature switch is provided to monitor exhaust air temperature. This switch is
electrically interlocked with the load application controls to prevent load application if the resistor
stack exhaust temperature exceeds 375

F (OVERTEMP light comes on).