77
SERVICING
Motor Checks
WARNING
HIGH VOLTAGE
Disconnect ALL power before servicing or installing
this unit. Multiple power sources may be present.
Failure to do so may cause property damage, personal
injury or death.
1. Disconnect power to air handler or modular blower.
NOTE:
Motor contains capacitors that can hold a charge
for several minutes after disconnecting power. Wait 5
minutes after removing power to allow capacitors to
discharge.
2. Disassemble motor as described in steps 2 through 4
above.
3. Locate the 3-circuit harness from the motor. Using an
ohmmeter, measure the resistance between each motor
phase winding. The resistance levels should be equal.
Replace the motor if the resistance levels are unequal,
open circuited or short circuited.
4. Measure the resistance between each motor phase
winding and the motor shell. Replace the motor if any
phase winding is short circuited to the motor shell.
5. Reassemble motor and control/end bell in reverse of
disassembly. Replace blower assembly into air handler or
modular blower.
S-16H ECM CFM ADJUSTMENTS DVPTC/MBVC
This section references the operation characteristics of the
DVPTC/MBVC models. The MBVC models utilize an integrated
air handler control. The air handler control provides ECM blower
motor control and includes all dipswitches necessary to set up
the cooling, heat pump and electric airflow characteristics.
The control has three banks of dipswitches: a bank for cooling
airflow and trim adjustment, a bank for selecting one of (4)
enhancement profiles and enabling dehumidification, and a bank
for selecting the installed electric heater kit size. Adjustments
are made by selecting the appropriate ON/OFF combinations of
the dipswitches. The dipswitches along with their functions are
shown in the figures below.
Cooling Airflow Dipswitches
- Used to set the desired cooling
airflow
Cooling Airflow Speed Tap (* indicates factory setting)
Tap A
1
OFF ON
2
Tap B
1
OFF ON
2
Tap C
1
OFF ON
2
Tap D*
1
OFF ON
2
Airflow Adjust Dipswitches - Used to adjust the a/-10%
Airflow Adjust Taps (* indicates factory sett ing)
Normal*
3
OFF ON
4
+10%
3
OFF ON
4
-10%
3
OFF ON
4
Normal
3
OFF ON
4
Ramping Profile Dipswitches
- Used to select a comfort profile for
the cooling mode.
Cooling Airflow Ramping Profiles (* indicates factory
setting)
Tap A*
5
OFF ON
6
Tap B
5
OFF ON
6
Tap C
5
OFF ON
6
Tap D
5
OFF ON
6
Dehumidification Disable/Enable Dipswitch
- Reduces cooling
airflow by ~ 15% when enabled AND when used with a
humidistat (such as DEHUM1). Airflow is reduced when a call for
cooling is present and the humidistat is open.
7
8
OFF ON
DEHUM
Unused
Move to the ON position to
enable dehumidification
Electric Heater Airflow
- Airflow for installed electric heaters is
set by adjusting the dipswitches to the appropriate heater size.
Electric Heating Airflow (* indicates factory setting)
21 kW*
9
OFF ON
10
11
20 kW
9
OFF ON
10
11
15 kW
9
OFF ON
10
11
10 kW
9
OFF ON
10
11
8 kW
9
OFF ON
10
11
6 kW
9
OFF ON
10
11
5 kW
9
OFF ON
10
11
3 kW
9
OFF ON
10
11
Electric Heating Airflow (* indicates factory setting)
The table on the following page indicates the airflow that
corresponds to the available dipswitch settings.
