DXR2 applications also permit electric heating coil control in addition to heat pump control. They are then operated as reheaters and only enabled if the heat pump positioning signal is fully open.
Plant diagram
Figure: Example for a heat pump with electric reheater
Key:
DXR2… | Automation station |
| HP | Heat pump |
D1 | Presence |
| R1 | Room operator unit |
D2 | Window contact |
| Q1 | Fan |
|
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| YR | Electric heating coil |
Sequences
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| |||
Y | Output signal heat pump |
| TR | Room temperature |
YR | First stage electric reheater |
| SpH | Effective heating setpoint |
YH | Heat pump heating |
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Figure: 1-stage electric reheater
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| |||
Y | Output signal heat pump |
| TR | Room temperature |
YH1 | First stage electric reheater |
| SpH | Effective heating setpoint |
YH2 | Second stage electric reheater |
| YH | Heat pump heating |
Figure: 2-stage electric reheater
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| |||
Y | Output signal heat pump |
| TR | Room temperature |
YR | Modulating electric heating coils |
| SpH | Effective heating setpoint |
YH | Heat pump heating |
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|
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Figure: Modulating electric reheater
Actuators
Electric heating coils, controlled via an analog output on the DXR2 room automation station, can receive an enable via a relay or triac on the DXR2.
Safety thermostat
A binary overtemperature (open contact) protection can be connected on the DXR2 for all versions of the electric reheating application. The application switches off the electric reheater at device protection priority if overtemperature protection is enabled.
Description | Name | Default value |
|---|---|---|
Enable overtemperature detector input 0:No | EnOvrTDetIn | 0:No |
WARNING
Improper installation of electric heating coils can result in fire and cause destruction of life and property.
- Install a high temperature cut-out switch on all electric heating elements.
- Ensure that all wiring and installation conform to applicable safety codes and regulations.