Adjustment - Carrier 42S Series Instruction Manual

CN4 – CONDENSATE OVERFLOW SWITCH
1. Low voltage condensate switch shuts down the unit when the
water level in the drain pan reaches an unsafe level.
a. Switch is normally closed and opens on an increase in
water level.
2. When contact activated, then
a. Motor OFF
b. Valve Actuator OFF
c. Electric Heat OFF
d. Power to controller remains ON
3. OVF LED indication when condensate switch activated
CN5 – 2-STAGE COOLING/HEATING
1. Available with 2-stage coil for part load
2. 24V On/Off, 24V Floating, 0-10V Proportional control
3. CL2 or HT2 LED indication when either 2- stage cooling or
heating activated
CN6 – 1-STAGE COOLING/HEATING
1. Available with 2-stage coil for part load
2. CLG or HTG LED indication when either 1-stage cooling or
heating activated.
CN7 – CLASS II TRANSFORMER
1. 40VA, 75VA option
2. 24V LED activated when powered
CN8 – INCOMING POWER
CN9 – PSC MOTOR
1. 3-Speed application
2. Either LOW/MED/HI activated when a speed is selected
CN10 – EC MOTOR
1. 3-Speed application
2. Solid State switching
3. Either LOW/MED/HI activated when a speed is selected
4. ECM LED indicates speed control is powered
5. 0-10V LED intensity indicates increasing speed
ECM Fan Speed Adjustment
1. If the unit is equipped with an ECM blower, additional steps
may be required during the air balancing process. Review
project submittals or order acknowledgment to determine
which ECM control scheme the unit has. Alternatively, match
the control board to the illustrations.
CAUTION
Both of the procedures described below require the control
box to be powered while adjustments are made. Line voltage
components are concealed behind a secondary cover. Howev-
er, installer should still take all reasonable precautions.
NOTE: The unit has been factory configured to produce PSC
equivalent airflow on high speed, with medium and low speed set
at 80% and 60% of high, respectively. If these setting are accept-
able, then no further configuring is required.
If alternative airflows are desired, use board mounted pots to ad-
just the airflow associated with each input.
To reset to initial factory settings, reference the voltages found on
the sticker next to the pots.
APPENDIX C — CONTROLS OPERATION (CONT)
Each output can be adjusted from 0 to 100% of the motor's factory
programmed operating range. Use voltmeter and airflow chart (on
control box cover) to set values.
Adjusting the potentiometers requires the use of a Multi-meter ca-
pable of measuring 0~5 vdc. See steps below.
1. Only trained and qualified individuals should attempt to
adjust or service components on any electrical component.
Failure to follow safety rules could result in electrical shock
or hazard.
2. 24 VAC power must be supplied to ECM board to make
adjustments.
3. Set the electrical multimeter to Volts Direct Current (Vdc) on
the 0~5 or 0~20 Vdc scale.
4. Attach black (negative) lead of meter to the "Com" terminal
to the left of the potentiometers and below the Status light.
5. Attach the red (positive) lead of the meter to the terminal
below the Potentiometer needing adjustment.
a. High Speed: Using a small screwdriver, turn the H ADJ
potentiometer (CW for increasing speed, CCW for
decreasing speed).
b. Medium Speed: Using a small screwdriver, turn the M
ADJ potentiometer (CW for increasing speed, CCW for
decreasing speed).
c. Low Speed: Using a small screwdriver, turn the L ADJ
potentiometer (CS for increasing speed, CCW for
decreasing speed).
VARIABLE AIRFLOW FOR 0-10VDC
If a factory provided thermostat or DDC controller is utilized, then
the unit is already correctly configured. Carrier recommends using
the specified thermostat or DDC controller to commission the unit
whenever possible. However, the blower can be started and oper-
ated without the thermostat. Consult factory for further instruction.
ECM VARIABLE AIRFLOW FOR 0-10VDC
No control board is required and no field adjustments are possible.
Motor uses 0-10VDC signal directly. See control box label. Fan
enable at 1.5VDC.
GROUND TAB CONNECTION
1. For mulitmeter diagnostics
LED Function and Outcomes
Refer to Table G and Fig. G for functions and commands.
A
Fig. G — LED Functions
38
B C D E F G H I
J
K
L