(Mar, 2012)
Compact CWE Series Installation, Operation & Maintenance Manual
Air Technology Systems, Inc.
1.6.3 Smoke Detector
Optionally mounted in the return air stream, a
photo-electric smoke detector is used to sense the
presence of smoke and signal the controller when a
smoke alarm condition exists.
1.6.4 Firestat
Optionally mounted in the return air stream, a fi re de-
tector senses high return air temperature and signals
the controller when a fi re alarm condition exists.
1.6.5 Auto Transfer Switching
An automatic transfer, main power switching system
is optionally available for critical operations. With this
option, two main power service disconnect switches
are provided on the door of the cabinet to connect
two independent power sources (see Figure 3). If the
user selectable main power source is interrupted or,
if a phase loss or imbalance occurs, the automatic
transfer switching circuitry immediately transfers
operation of the precision A/C system to a secondary
power source. If power is transferred, the system
controller provides an alarm signal and the alarm
display indicates which power source failed. When
the primary power source is functionally restored,
the operation of the A/C system is automatically
transferred back to the primary power source.
Figure 3- Auto Transfer Disconnect Switches
OPTIONAL DUAL SERVICE
DISCONNECT SWITCHES
(LOCATION MAY VARY)
INDICATOR LIGHTS
(OPTIONAL)
FRONT DOOR OF
A/C SYSTEM
1.6.5.1 Preferred Power Selector Switch
A preferred power selection switch (Figure 4) is
included with the auto-transfer switching option. It is
either mounted on the front door of the cabinet or it
may be mounted inside the cabinet to the top of the
electric box (see Figure 2). This switch may be used
to manually transfer the power source and/or test the
auto transfer switching function.
Figure 4- Preferred Power Selection Switch
POWER
PREFERRED POWER SWITCH
A
POWER
B
POWER
SUPPLY A
POWER
SUPPLY B
1.6.5.2 Indicator
Lights
As an additional option, an indicator light may be
provided above each main power service discon-
nect switch (see Figure 3). A light illuminates above
the switch that’s selected to supply power to the A/C
system whether the unit is running or not, indicating
that power is available at the switch.
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