Siemens RDF20U User Manual

Technical Instructions RDF20U Room Temperature Controller with LCD
Document Number 155-334 for Two-Pipe Fan Coil Units with Electric Heat
September 27, 2007
Page 10 Siemens Industry, Inc.
Mounting,
Installation and
Commissioning
Notes, Continued
▪ Installation Instructions are included with the controller.
WARNING:
• Sensor inputs 7, 8, and 9 carry live voltage potential. If the sensor’s
cables must be extended, the cables used must be suited for live
voltage.
• The cables used must meet the insulation requirements for live
voltage.
Calibrating the Sensor
If the room temperature displayed by the controller is inconsistent with the room
temperature being measured, the temperature sensor of the RDF20U can be
recalibrated. To recalibrate, change Parameter P09.
Specifications
Power Supply
Operating voltage 24 Vac, +20/-25%
Frequency 50/60 Hz
Power consumption 6 VA maximum
Fan control outputs 12, 11, 10-N 24 Vac
Rating 5 (3) A maximum
Valve control output 4-2 (NO) 24 Vac
Rating 5 (3) A maximum
Valve control output 5-2 (NC 24 Vac
Rating 5 (3) A maximum
Electric heat control output 6-2 (NO) 24 Vac
Rating 5 (3) A maximum
Return air temperature sensor QAH11.1 safety class II
status input 9-8 NTC resistor 3K  at 77°F (25°C)
Changeover—status input 7-8 QAH11.1, safety class II
NTC resistor 3K  at 77°F (25°C)
Status input D1 and GND
Contact sensing SELV 6 to 15 Vdc/ 3 to 6 mA
Insulation against live voltage 4 kV, reinforced insulation
Operating action Selectable (NO/NC)
Permissible cable length with copper 262 ft (80 m)
cable 14 AWG for connection to terminals
7, 8, and 9 and D1, GND.
Operational Data
Setpoint setting range 41°F to 95°F (5°C to 35°C)
Control deviation at 77°F (25°C) + 1°F (0.5K) maximum
Switching differential in Heating mode, 2 K (3.6°F)
adjustable
Switching differential in Cooling mode, 1 K (1.8°F)
adjustable
Dead zone X
dz
in Normal operation, 2 K (3.6°F)
adjustable
Setpoint differential W
D
, adjustable 2 K (3.6°F)
Setpoint, Economy mode , heating, 61°F (16°C)
adjustable
Setpoint, Economy mode , cooling, 82°F (28°C)
adjustable
Setpoint, Standby , heating, adjustable 46°F (8°C)
Setpoint, Standby , cooling, adjustable OFF

Siemens RDF20U Specifications

General

Brand	Siemens
Model	RDF20U
Category	Temperature Controller
Language	English