RCU50U and RCU50.2U Room Temperature Controllers Technical
Instructions
For VAV Systems
Document Number 155-327P25
Rev. 1, March, 2002
Siemens Building Technologies, Inc.
Page 5
Mechanical Design,
Continued
The screw terminals are mounted on the base. The DIP switches and the potentiometer
are located at the rear of the unit. To access the DIP switches, remove the controller
from the controller base. See Figure 7.
Figure 7. Dip Switch Setting.
Table 3. RCU50U DIP Switches.
DIP Switch No.
Meaning
Position ON
Position OFF
1
Operating mode changeover
via external switch
Changeover between
normal operation and energy
saving mode
Changeover between normal
operation, energy saving and
standby
1
2
Operating action of switch
for external operating mode
changeover
Changeover activated when
contact of switch is closed
(N.O.)
1
Changeover activated when
contact of switch is open
(N.C.)
3
Standby
OFF
Frost protection mode (heating
output ON at a set point of 46°F
(8°C)
1
4
P-band
2°F (1°C) in heating mode
1°F (0.5 C) in cooling mode
7°F (4°C) in heating mode
1
3.5°F (2°C) in cooling mode
1
5
Cooling signal output in
energy saving mode
Active Inactive
1
Table 4. RCU50.2U DIP Switches.
DIP Switch
No.
Meaning
Position ON
Position OFF
1
Signal inversion 0 to 10 Vdc
Output signal 0 to 10 Vdc
1
Output signal 10 to 0 Vdc
1. Factory setting
Accessories
ARG70
Adapter Plate for 2 × 4-inch or 4 × 4-inch conduit boxes
QAH11.1 Changeover/remote
sensor
Notes
•
In systems without automatic changeover, the temperature sensor can be replaced
by an external switch for manual changeover.
•
In systems with cooling only operation, the controller changeover input (terminals 2
and 3) must be bridged.
•
In systems with heating only operation, do not connect sensor to, or bridge
controller changeover input (terminals 2 and 3).
