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Siemens Building Technologies
Installation guide
CA2Z3884en
Building Automation
08.2001
6
Relay outputs
The volt-free relay outputs are used for fan control. The following applies to the cables:
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Note the maximum rating of the relay contacts (refer to the data sheet of the room
controller concerned)
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The sizing and routing of cables depends on the connected load and the local
installation regulations.
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Fuse ratings depend on the room controller used. Please refer to the relevant
controller data sheet.
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The cables must be secured with cable restraints.
The RXA22.1 controller has an additional relay contact (Q44) for switch control of an
electric heating coil. Note the following for this relay contact:
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The maximum resistive load is 1.8 kW. Loads above this value cause excessive
wear of the contact in the case of PWM operation
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An external fuse of max. 10 A must be provided to protect the pcb tracks in the
controller.