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AKD-20 AR / Entellisys AR Low-voltage Switchgear
Section 8. Operating the Switchgear
Cooling Fan Control Module
General
AKD-20 AR and Entellisys AR switchgear may be provided
with a front mounted auxiliary ventilation compartment,
Figure 8.16.
The GA50 (AKD-20 AR) and EE50 (Entellisys AR) circuit breaker
compartment is provided with an integrally mounted cooling
fan system. The cooling fan system, when provided, is
contained within the front mounted auxiliary ventilation
compartment. When a front mounted auxiliary ventilation
compartment contains a fan cooling system, the instrument
tray directly above the front mounted ventilation
compartment will be provided with the components shown in
Figure 8.17.
In AKD-20 AR applications, the fan control is initiated by the
"Current Alarm 2" feature of the trip unit which signals a fan
control circuit to turn the fans on or off. Refer to Figure 8.18
for a typical fan cooling circuit diagram.
In Entellisys AR applications, the fan control is initiated by the
Entellisys Messenger which signals a fan control circuit to turn
the fans on or off. Refer to Figure 8.19 for a typical fan
cooling diagram.
The fan control circuit requires 120Vac control power which is
normally provided by the switchgear control power
transformer. The power requirements for each fan is 0.3
amps @ 120Vac (2 fans installed).
Remote monitoring of the fan control circuit is optionally
available.
NOTICE: Variations of the fan control circuit may be
provided. Operators should review and understand the
shop order drawings and documents provided with the
equipment from the factory to confirm final fan control
circuitry.
Table 8.1 provides the current threshold values that the circuit
breaker trip unit's "Current Alarm 2" function (AKD-20 AR)
should be programmed to initiate the fan cooling system.
Refer to DEH-4567 for details on programming the circuit
breaker trip unit. For Entellisys AR circuit breaker
compartments, the initiation of the fan cooling system will be
automatically managed by the Entellisys Messenger. Refer to
DEH-551 for additional information.
Operation of the switchgear, for an extended period of time,
above the threshold limits shown in Table 8.1 without a
properly working fan cooling system will not create an unsafe
condition but is not recommended.
55
Courtesy of NationalSwitchgear.com
Table 8.1 Current Alarm 2 Settings for Cooling Fan System
Section Width
Circuit Breaker
(inches)
GA50
38
NOTICE: The circuit breaker(s) referenced in Table 8.1 must
be configured with the "Current Alarm 2" trip unit option
and this function must be set per Table 8.1 for proper
operation of the fan cooling system.
Figure 8.16 Front mounted auxiliary ventilation
compartment
EntelliGuard Circuit Breaker
(1)
Instrument Tray Panel
(2)
Front Mounted Auxiliary Ventilation Compartment
(3)
Figure 8.17 Fan control instrument tray panel
Fan Control Power Fuse
(1)
EntelliGuard Breaker Current Alarm Indicating Light
(2)
Fan Relay "On" Indicating Light
(3)
Fan "On" Indicating Light(s)
(4)
Illuminating Fan Control Switch
(5)
©2016 General Electric. All rights reserved.
DEH-41473
Current Alarm 2 (Amperes)
ON Set Point
OFF Set Point
4,500
4,500
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