
IM 738-2
19
Introduction:
Controls, Settings, and Functions
PC7
Airflow proving
switch
Senses supply fan pressure to
prove airflow
Auto
Supply fan
section
.10" w.c. (25 Pa)
.05-5" w.c.
(12.5–1245.4 Pa)
.05" w.c.
(12.5 Pa), fixed
060015801
PS1, 2 Pumpdown switch Used to manually pump down
compressor
N/A
Condenser
control box
N/A
N/A
N/A
01355000
RAE
Return air
enthalpy sensor
Used to compare return air
enthalpy to outside air
enthalpy (used with OAE)
N/A
Economizer
section
N/A
N/A
N/A
049262202
RAT
Return air
temperature
sensor
Senses return air temperature
N/A
Return air
section
N/A
N/A
060004705
SD1
Smoke detector,
supply air
Initiates unit shutdown if
smoke is detected
Manual Discharge air
section
N/A
N/A
N/A
04925001
SD2
Smoke detector,
return air
Initiates unit shutdown if
smoke is detected
Manual
Return air
section
N/A
N/A
N/A
04925001
SPS1
Static pressure
sensor duct #1
Converts static pressure
signals to voltage signals
N/A
Main control
box
N/A
0–5" w.c.
(0–1245.4 Pa)
1–6 VDC out
N/A
049545007
SPS2
Static pressure
sensor duct #2
Converts static pressure
signals to voltage signals and
sends them to MicroTech II
controller
N/A
Main control
box
N/A
0–5" w.c.
(0–1245.4 Pa)
1–6 VDC out
N/A
049545007
Static pressure
sensor: building
(space) pressure
Converts static pressure
signals to voltage signals.
N/A
Main control
box
N/A
-025–0.25" w.c.
(-62.3–62.3 Pa)
1–5 VDC out
N/A
049545006
SV1, 2 Solenoid valve
(liquid line)
Closes liquid line for
pumpdown
N/A
Condenser
section
N/A
N/A
N/A
See parts
catalog
SV5, 6 Solenoid valve
(hot gas bypass)
Closes hot gas bypass line for
pump-down
N/A
Condenser
section
N/A
N/A
N/A
111011001
S1
System switch
Shuts off entire control circuit
(except crankcase heaters)
N/A
Main control
box
N/A
N/A
N/A
001355000
S7
ON-OFF-AUTO
switch
Used to manually switch unit
N/A
Main control
box
N/A
N/A
N/A
Table 3: Controls, settings, and functions (continued)
Symbol
Description
Function
Reset
Location
Setting
Range
Differential
Part no.