Whilst considering a replacement of a Danfoss/Myson FH-BU where much of the wiring disappears into trunking making end-to-end searching of the wiring very difficult, I have two twin core cables, each with their blue wire cut off at the external sleeve, leaving the brown wire of each cable terminated into one terminal of a two termination connector of an Omron GRN6-1 one pole relay.I.e. Two relays each with only one wire connected. One relay is marked with symbol for a heat source -the other being a pump symbol. All very self evident , but why only one wire connected which would appear to make the relay function redundant? However, if you disconnect the pump single wire, then the UFH pump doesn’t operate on demand from the thermostat. So it DOES SOMETHING - the question is what and where doi connect Iona putative Heatmiser wiring centre? Photo attached - many thanks for any suggestions.
Odd wiring
- Thread starter kbjpick
- Start date
It appears to be a live output. The live is being fed to a connection on the relay, from the PCB - probably through the "Selection" wires next to the relay.
When the relay is turned on, live is provided out of the relay, to the pump.
As above, the neutral is picked up elsewhere.
I don't know by how much they differ, but here is a link to the FH-RT manual - it might give you some clues:
5.3 Thermostat Test Mode; 5.4 Thermal Actuator Output Testing; 5.5 Alarm Function; 5.6 Thermal Actuator & Pump Exercise - Danfoss FH-RT Installation & Operating Instructions Manual [Page 5]
Danfoss FH-RT Manual Online: 5.3 thermostat test mode, 5.4 Thermal Actuator Output Testing, 5.5 Alarm Function, 5.6 Thermal Actuator & Pump Exercise, 5.7 No/Nc Thermal Actuator Settings, 5.8 “Cooling” Mode, 6.0 Boiler And Pump Interlock Setting. This Mode Is Used To Test Thermostat...
www.manualslib.com
Many thanks for input and link to manual - connection it does appear to be a switched live with neutral picked up elsewhereIt appears to be a live output. The live is being fed to a connection on the relay, from the PCB - probably through the "Selection" wires next to the relay.
When the relay is turned on, live is provided out of the relay, to the pump.
As above, the neutral is picked up elsewhere.
I don't know by how much they differ, but here is a link to the FH-RT manual - it might give you some clues:
5.3 Thermostat Test Mode; 5.4 Thermal Actuator Output Testing; 5.5 Alarm Function; 5.6 Thermal Actuator & Pump Exercise - Danfoss FH-RT Installation & Operating Instructions Manual [Page 5]
Danfoss FH-RT Manual Online: 5.3 thermostat test mode, 5.4 Thermal Actuator Output Testing, 5.5 Alarm Function, 5.6 Thermal Actuator & Pump Exercise, 5.7 No/Nc Thermal Actuator Settings, 5.8 “Cooling” Mode, 6.0 Boiler And Pump Interlock Setting. This Mode Is Used To Test Thermostat...
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