Operating Modes - Siemens RDF30U Technical Instructions

RDF30U Room Temperature Controller with LCD
For Four-Pipe Fan Coil Units
Cooling Mode
Return Air Temperature
(Optional)

Operating Modes

Normal Mode
Economy Mode
Standby
Siemens Industry, Inc.
2. the valve has been open for more than one minute (Parameter 19)
NOTE:
Output terminals 5 and 2 are the inverse of terminals 4 and 2.
Output terminals 6 and 2 (neutral) are open (0 Vac) when:
1. the measured room temperature is at half the switching differential below the
Cooling mode setpoint (W + Xdz – 1/2 SDC), and
2. the valve has been open for more than one minute (Parameter P19).
Output terminals 6 and 2 (neutral) are closed (24 Vac) when:
1. the measured room temperature is at half the switching differential above the
Cooling mode setpoint (W + Xdz + 1/2 SDC), and
2. the valve has been closed for more than one minute (Parameter P20).
Figure 1. Water-based Fan Coil
Heating and Cooling Mode.
The RDF30U 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 9-8 and then operates automatically according to that temperature.
Heating or Cooling mode with automatic changeover and manually selected fan speed
(III, II or I). In Normal mode, the controller maintains the adjusted setpoint in Heating
mode and; in Cooling mode, a temperature level represented by the setpoint plus the
dead zone.
A potential-free operating mode changeover switch can be connected to status input
D1-GND. When the switch closes its contact (due to an open window, for instance), the
operating mode will change from Normal to Economy. In this operating mode, the
relevant setpoints of heating or cooling are maintained (adjustable in Parameters P01
[setback temperature for heating] and P02 [setback temperature for cooling]). The
operating action of the switch (NC or NO) can be selected.
The relevant setpoints of heating and cooling are maintained when in Standby " "
mode, provided those setpoints have been adjusted. The standby temperature setting
for Heating mode in Parameter P03 is adjustable from 41°F to 68°F (5°C to 20°C) or
"OFF" and the setting for Cooling mode in Parameter P04 is adjustable from 70°F to
95°F (21°C to 35°C) or "OFF".
T Room temperature
SDH Switching differential, Heating
SDC Switching differential, Cooling
Xdz Dead zone
w Room temperature setpoint
YH Heating valve, 24 Vac control output
YC Cooling valve, 24 Vac control output
Technical Instructions
Document Number 155-335
September 27, 2007
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