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Sizes B04- -B07
Refer to charts (Fig. 36- - 39) to determine the proper
leaving condenser liquid temperature at the test condition
compressor discharge pressure.
Accurate pressure gauge and temperature sensing meter
are required. Connect the pressure gauge to the service
port on the discharge line. Mount the temperature sensing
device on the liquid line leaving the outdoor coil and
insulate it so that outdoor ambient temperature does not
affect the reading.
Example (Fig. 36):
Unit B04
Compressor Discharge Pressure 370psig (2550kPA)
Leaving Condenser Liquid Temperature 105_F (40.6_C)
NOTE:
When using these Humidi- - MiZer charging
charts, it is important that the system be operating in
Reheat1 mode: cooling thermostat in demand, humidistat
in demand. The subcooling/reheat dehumidification coil
liquid line solenoid vavle MUST be energized to use the
charging charts and the discharge gas reheat solenoid
valve must be de- - energized (valve closed). The outdoor
motor speed controller must be jumpered to run the fan at
full speed during charge checking.
Bypass 32LT Motormaster
32LT controller is mounted on a bracket attached to unit
base pan beneath the main control box. To bypass the
32LT and run the outdoor fan at full speed:
1. Disconnect power to unit.
2. Remove the 32LT cover to access the splice box.
3. Locate the two line connections with BLK wires.
4. Separate both 32LT BLK leads from control box
BLK wire and the BLK wire from OFM.
5. Splice the control box BLK wire to the OFM wire.
6. Restore power to unit.
When the charge check/adjustment procedure is complete,
restore the 32LT function by disconnecting unit power,
then reversing steps 5 through 2 above, concluding with
replacing and securing the 32LT cover. Restore power to
the unit.
Charge check and adjustment
Read the discharge pressure gauge; record the pressure.
Read the liquid line temperature. Plot the test discharge
pressure (using the X- - axis) and test liquid temperature
(using the Y- - axis) on the unit charging chart. If the
plotted test condition point is to the left/above the
charging curve, add refrigerant. If the plotted test
condition is to the right/below the charging curve,
carefully recover some of the charge.
Allow the unit to operate in Reheat1 mode for
approximately five minutes, then recheck conditions
against the charging chart. Repeat the charge adjustment
procedure until the plotted test condition falls on the
charging curve.
When charging procedure is completed, remove the
bypass wiring on the Motormaster control. Readjust the
cooling thermostat setting and the humidistat setting to
appropriate design setpoints.
Sizes E08- -E14
Unit sizes E08 through E14 (two circuit designs) use the
same charging chart and general method as discussed
above under Base Cooling Units. See Fig. 30- - 34. During
the charge adjustment step, the unit will be run in the
Cooling mode; thermostat will be Cool demand,
humidistat will be open for no demand. The standard
Motormaster head pressure control device will be
jumpered to operate all fans at full speed.
Bypass Motormaster Controllers Unit sizes
E08- -E12
32LT controller is mounted on a bracket attached to unit
base pan beneath the main control box. To bypass the
32LT and run both outdoor fans at full speed:
1. Disconnect power to unit.
2. Remove the 32LT cover to access the splice box.
3. Locate the two line connections with BLK wires.
4. Separate both 32LT BLK leads from control box
BLK wire and the two BLK wires from OFM1 and
OFM2.
5. Splice the control box BLK wire to the two OFM
wires.
6. Restore power to unit.
When the charge check/adjustment procedure is complete,
restore the 32LT function by disconnecting unit power,
then reversing steps 5 through 2 above, concluding with
replacing and securing the 32LT cover. Restore power to
the unit.
Unit Size E14
Motormaster V (VFD- - based) controller provides head
pressure control on the size E14 unit. The controller is
mounted inside the blower compartment, on the wall to
left of blower. Bypassing this controller requires the
fabrication of a resistor- - wire assembly consisting of a 10k
ohm (1/2- - watt) resistor and two 20- - 18 ga. wire leads.
To bypass the Motormaster V and run the outdoor fan at
full speed:
1. Disconnect unit power. Lockout/tag- - out.
2. Remove MM- - V cover to expose the controller ter-
minal strip.
3. Disconnect the Pressure Transducer input wires at
terminals 2, 5 and 6.
4. Connect the resistor- - wire assembly at terminals 5
and 6. See Fig. 22.
5. Replace cover on MM- - V.
6. Check for clearances around the blower and belt.
7. Restore power to unit.
When the charge check/adjustment procedure is complete,
restore the Motormaster V function by disconnecting unit
power, then reversing steps 5 through 2 above. See Fig. 22
18
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