Maintenance - Siemens RAB20 Series Technical Instructions

Technical Instructions
Document Number 155-526P25
March 2, 2007

Maintenance

Diagrams
Page 8
The room thermostat is completely maintenance-free. If inoperable, replace entire unit.
WARNING:
High voltage. Disconnect power before servicing. Metal part is not
grounded.
L
L
G1 G2 G3
I II III
M1
N
W
ON
SP
OFF
T[˚F]
SD
Heating Mode
RAB20 Series Two-pipe Fan Coil Room Thermostat
W Y
N1
AS
ZV
Figure 5. Wiring.
Y
ON
SP
OFF
SD
Cooling Mode
Figure 6. Operating.
AS Aqua sensor (by others)
G1 Control output fan speed I
(Low)
G2 Control output fan speed II
(Medium)
G3 Control output fan speed III
(High)
L Operating voltage
M1 3-speed fan
N Neutral
N1 Room thermostat
W Valve output, heating
Y Valve output, cooling
ZV Zone valve
SD Switching differential
SP Room temperature
setpoint
T Room temperature
W Valve output signal
T[˚F]
heating
Y Valve output signal
cooling
Siemens Building Technologies, Inc.