Control Options Module (Psio2) - Carrier 48FP Controls Operation And Troubleshooting

CONTROL OPTIONS MODULE (PSIO2) — See Fig. 47.
The options module controls the following features:
1. Relative humidity sensor. This feature requires a field-
supplied, 4-wire, 2 to 10 v RH (relative humidity)
sensor.
2. Outdoor-air cfm sensor. This feature requires a 4-wire,
field-supplied, mass flow sensor to input a 2 to 10 v
signal.
3. Indoor-air quality. This feature uses a field-supplied,
4-wire, carbon-dioxide sensor to input a 2 to 10 v
signal.
4. Fire and smoke routines. This is accomplished through
field-supplied remote switch inputs.
5. Humidifier function. This feature provides control of a
field-installed humidifier.
6. Discrete timer output. This output permits control of
timed functions such as parking lot lights.
7. Hydronic valve control. The PSIO2 module provides
outputs to control a field-installed hydronic coil valve.
8. Suction gas thermistor input.
9. Freezestat switch input.
10. Supply Air Temperature Reset from external signal.
Requires field-supplied 2 to 10 vdc signal.
LEGEND
COMM — Communications Bus
NC — Normally Closed
Fig. 46 — High-Voltage Relay Modules
NO — Normally Open
PWR — Power
11. Motormaster® (Stage 1) controls (size 088 and
104 only).
12. External alert signal contact (size 088 and 104 only).
ACTUATORS — The actuators for these units are positioned
by a 4 to 20 mA signal from the microprocessor. The actuators
contain a series of DIP (dual in-line package) switches that de-
termine the maximum travel of the actuator.
See Table 63 for the degrees of travel and the correct DIP
switch settings for each actuator.
When installing actuator linkage, actuator should be pow-
ered to its fully open position. The linkage should then be con-
nected so that the actuator does not stall against a fully open
damper.
LEGEND
COMM — Communications Bus
PWR — Power
Fig. 47 — Control Options Module (PSIO2)
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