2-10
T-294-01
Orange wire
Power
Red wire
Output
Brown wire
Ground
Input voltage
5 vdc
i. Humidity Sensor
Output voltage
0 to 3.3 vdc
i. Humidity Sensor
(HS) -- Optional
Output voltage readings verses relative humidity (RH) percentage:
(
)
p
30%
0.99 V
50%
1.65 V
70%
2.31 V
90%
2.97 V
2.4 POWER AUTOTRANSFORMER (TRANS)
WARNING
Do not attempt to remove power plug(s)
before turning OFF start-stop switch (ST),
unit circuit breaker(s) and external power
source.
Make sure the power plugs are clean and dry
before connecting to any power receptacle.
a. Step-Up Power Autotransformer
The modular transformer (if equipped) is located under
the condenser coil on the left-hand side of the unit (see
Figure 2-7).
The modular transformer (item 1, Figure 2-7) provides
380/460 vac, 3-phase, 50/60 hertz power to the unit
when the 230 vac (black) power cable is connected to a
190/230 vac, 3-phase power source. The module, in
addition to the transformer, includes a 230 vac cable and
a receptacle to accept the unit 460 vac power plug. The
modular transformer may be equipped with an optional
circuit breaker (CB-2).
WARNING
Do not attempt to unplug the power cable
connected to the autotransformer before
performing the following operations: Move
the start-stop switch (ST), the unit circuit
breaker(s), CB-1 and CB-2 (if equipped)
and any external power source to their OFF
positions.
b. To Operate Unit on 190/230 vac Power Supply
1. Make sure that the start-stop switch (ST, on control
panel) and circuit breaker (CB-2 if equipped, on the
modular transformer) are in position “0” (OFF).
Make sure the 460 vac power plug is locked into the
receptacle on the modular transformer and circuit
breaker (CB-1, in the control box) is in position “1”
(ON).
2. Plug the 230 vac (black) cable into a de-energized
190/230 vac, 3-phase power source. Energize the
power source. Set circuit breaker (CB-2 if
equipped) to position “1” (ON). Close and secure
control box door and place the start-stop switch
(ST) in position “1” (ON) to start the unit.
c. To Operate Unit on 380/460 vac Power Supply
1. Make sure start-stop switch (ST, on control panel)
and circuit breaker (CB-1, in the control box) are in
position “0” (OFF).
2. Plug the 460 vac (yellow) cable into a de-energized
380/460 vac, 3-phase power source. Energize the
power source. Place circuit breaker (CB-1) in
position “1” (ON). Close and secure control box
door and then place the start-stop switch (ST) in
position “1” (ON) to start the unit.
1
2
3
4
1. Dual Voltage Modular Transformer
2. Circuit Breaker (CB-2) 230V (Optional)
3. Transformer Bridging Unit (TBU)
4. 460 vac Power Receptacle
Figure 2-7. Power Autotransformer
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