Siemens RDF20U Скачать руководство пользователя страница 2

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 2 

Siemens Industry, Inc.

 

 

 

Accessories 

ARG70 

Adapter plate for 4-inch × 4-inch or 2-inch × 4-inch conduit boxes 

141-570  

Lockable thermostat guard 

QAH11.1 

Changeover/remote temperature sensor 

 

Warning/Caution 
Notations 

WARNING: 

 

Personal injury or loss of life may occur if you do not perform 
a procedure as specified. 

 

CAUTION: 

 

Equipment damage may occur if you do not follow a 
procedure as specified. 

 

Operation 

The controller acquires the room temperature via its integrated sensor or optional 
external return air temperature sensor (QAH11.1) and maintains the setpoint by 
delivering two-position valve control and electric heat output commands. 

The switching differential is 2 K (3.6

F) in Heating mode and 1 K (1.8

F) in Cooling 

mode (adjustable). 

Fan Operation 

The fan is switched to the selected speed via control output 12, 11 or 10. 

When 

the “Temperature-dependent fan control“ function is activated (can be selected 

with DIP Switch No. 1), the fan is switched on/off depending on the temperature, 
together with the valve. 

It is switched off when any of the following occurs: 

• 

leaving the heating or cooling sequence, provided the “Temperature-dependent fan 
co

ntrol“ function is activated. 

• 

manually changing to Standby “ ” provided no setpoints (example, for freeze 
protection) are set and active. 

• 

activating an external operating mode changeover switch, provided application 
conditions do not call for Economy mode. 

• 

turning off the controller’s power supply. 

NOTE: 

To avoid overheating the electric heat or to prevent the thermal cut-out from 
responding, the fan will overrun for 60 seconds (default Parameter 21) when 
the electric heat is switched off. 

 

 

CAUTION: 

In the event of failure, the RDF20U cannot protect the electric heat against 
overheating. Therefore, the electric heat must be equipped with a separate 
safety device (high temperature detection thermostat). 

Display 

If DIP Switch No. 2 is set to ON (factory setting), the controller displays the measured 
room or return air temperature (unless parameters or setpoints are temporarily 
changed). If the DIP switch is set to OFF, the controller displays the Normal operating 
mode setpoint. In this case, the value of the current temperature reading can only be 
visualized temporarily by selecting Parameter P14. 

Содержание RDF20U

Страница 1: ... and Standby Operating mode changeover input for remote control Day Night Air movement control function for avoiding damage resulting from moisture Selectable installation and control parameters Display of room temperature or setpoint selectable Electronic minimum and maximum setpoint limits Operating voltage 24 Vac Application Typical use Control of the room temperature in individual rooms that a...

Страница 2: ...an is switched on off depending on the temperature together with the valve It is switched off when any of the following occurs leaving the heating or cooling sequence provided the Temperature dependent fan control function is activated manually changing to Standby provided no setpoints example for freeze protection are set and active activating an external operating mode changeover switch provided...

Страница 3: ...sured room temperature is half the switching differential above the Cooling Mode setpoint W and 2 the valve has been open for more than one minute Parameter 19 NOTE Terminal output 5 NC delivers a control command which is inverted to the control command at output 4 NO and can be used for Normally Open valves Automatic Changeover The water temperature measured by the changeover sensor QAH11 1 is us...

Страница 4: ...16 and exiting the parameter setting mode Return Air Temperature Optional The RDF20U provides control based on the measured room temperature or the fan coil unit s return air temperature It detects if a QAH11 1 cable temperature sensor is connected to input 8 9 and then operates automatically according to that temperature Electric Heat Active in Heating Mode NOTE This function is not active when u...

Страница 5: ...eating Mode Hot Water Plus Electric Heat Figure 5 Cooling Mode with Optional Electric Heat DIP Switch 4 ON Electric Heat Enabled Figure 6 Cooling Mode Chilled Water DIP Switch 4 OFF Electric Heat Disabled T F Room temperature w Room temperature setpoint wD Setpoint differential Y Heating cooling valve output voltage E Electric heat SDH Switching differential Heating SDC Switching differential Cool...

Страница 6: ...ous fan To avoid damage due to moisture in very warm and humid climates resulting from lack of air circulation in Economy mode for example in hotel rooms during unoccupied periods the fan can be kept running in Economy mode when activating Parameter P17 In this case the fan keeps running at the selected speed or at speed I if the operating mode selector is in Standby Setting the Control Parameters...

Страница 7: ... This parameter is in degrees Kelvin 1 K 1 8 F 0 5 K to 4 K 1 F to 7 F in increments of 0 5 K 2 K 3 6 F P11 P band in Cooling mode or switching differential cooling NOTE This parameter is in degrees Kelvin 1 K 1 8 F 0 5 K to 4 K 1 F to 7 F in increments of 0 5 K 1 K 1 8 F P12 Dead zone in Normal mode 0 5 K to 10 K 1 F to 18 F in increments of 0 5 K 2 K 3 6 F P13 Active temperature sensor no settin...

Страница 8: ...155 321P25 Mechanical Design The controller consists of two parts Plastic housing which accommodates the electronics the operating elements and the built in room temperature sensor Base The housing engages in the base and is secured with two screws The base carries the screw terminals The DIP switches are located at the rear of the housing Setting and Operating Elements Figure 7 RDF20U Components ...

Страница 9: ...erature sensor can be replaced by an external switch suited for live voltage for manual changeover In systems with continuous heating mode no sensor is connected to the controller s input In systems with continuous cooling mode the controller input 7 8 must be bridged Mounting Installation and Commissioning Notes Mounting location On a wall or inside the fan coil unit Do not mount in niches or boo...

Страница 10: ...put 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 t...

Страница 11: ...minals Figure 9 Wiring Terminals 1 2 24 Vac negative 3 24 Vac positive 9 Return air temperature sensor 8 Measuring neutral 7 Changeover sensor D1 GND Potential free operating mode changeover switch operating action can be selected 12 Control output Fan speed I 24 Vac 11 Control output Fan speed II 24 Vac 10 Control output Fan speed III 24 Vac 4 Control output Valve 24 Vac 5 Control output Valve 24...

Страница 12: ...ademarks of their respective owners 2007 Siemens Industry Inc Siemens Industry Inc Building Technologies Division 1000 Deerfield Parkway Buffalo Grove IL 60089 1 847 215 1000 Your feedback is important to us If you have comments about this document please send them to SBT_technical editor us sbt siemens com Document No 155 334 Printed in the USA Page 12 Dimensions In Inches Millimeters Figure 11 R...

Отзывы: