RDU20U, RDU50U and RDU50.2U Room Temperature Controllers
Technical Instructions
with LCD for Heating and Cooling Systems
Document Number 155-735
November 1, 2006
Siemens Industry, Inc.
Page 9
Specifications
Power Supply
Operating voltage
24 Vac +20%
Frequency
50/60 Hz
Power consumption
Maximum 4 VA
Control output 1
–5 (RDU50U and RDU50.2U)
0 to 10 Vdc
Resolution
39 mV
Effective current
M1 mA
Control output 4
–6 (RDU20U)
24 Vac
Return air temperature input 4
–3
QAH11.1 safety class 2
Changeover temperature input 2
–3
NTC resistor 3K ohm at 77°F (25°C)
(RDU50U) and RDU20U
8
–7 (RDU20U)
Dry contact D1 and GND
Contact sensing
6 to 15 Vdc/3 to 6 mA
Operating action
Normally Open (NO)
Maximum cable length 16 AWG
262 feet (80 m)
for connection to terminals 4, 2 and D1
Operational data
Setpoint setting range
41°F to 95°F (5°C to 35°C)
Control deviation at 77°F (25°C)
M1.6°F (0.9°C)
P-band in heating mode, adjustable
in 0.5K increments (1 Kelvin = 2°F)
0.5K to 4K
Factory setting
2K
P-band in cooling mode, adjustable
in 0.5K increments (1 Kelvin = 2°F)
0.5K to 4K
Factory setting
1K
Integral action time, adjustable
1 to 10 minutes
Factory setting
5 minutes
Setpoint (Energy Saving Mode ), heating
41°F to 65°F (5°C to 18°C)
Setpoint (Energy Saving Mode ), cooling
75°F to 95°F (24°C to 35°C)
Environmental
Conditions
Operation
Temperature
32°F to 122°F (0°C to 50°C)
Humidity
<95% rh
Shipping and storage
Temperature (RDU50U and RDU50.2U)
-13°F to 158°F (-25°C to 70°C)
(RDU20U)
-13°F to 140°F (-25°C to 60°C)
Humidity
<95% rh
Agency Approvals
Conforms to CE requirements
NEMA 1
General
Connection terminals
Use solid wires or prepared stranded
wires. 2 × 16 AWG or 1 × 14 AWG
Maximum 20 AWG
Weight
0.5 lb (0.23 kg)
Housing color
Cover
White
Base
Gray