Description
Pre-engineered relay adaptor for Hoyme damper interlock sequences. Select the model by appliance type and system voltage: relay ratings, interlock logic, and wiring are already matched and documented. Colour wiring diagrams included in every box. 24 models cover the full range of residential and light commercial Hoyme damper interlock applications. The 8 most common are shown below. See the full model selector on this page for all 24.
✓ Relay ratings pre-matched to the safety circuit: getting this wrong loads the safety circuit and causes nuisance lockouts or damage; the ADP is matched at the factory so the field wiring is the only variable
✓ Colour wiring diagrams included: every box; specific to the model; satisfies the documentation requirement that inspectors look for on permitted installations
✓ A/C circuit not affected: all ADP models are designed so relay logic does not affect the air conditioning circuit; documented in the wiring diagram
✓ Relays field-replaceable: a relay failure does not require replacing the complete ADP assembly; up to 4 relays per enclosure depending on model
✓ Compatible with all Hoyme end switch outputs: HOM (SF1/SF2), HAC (SPO/SPC), MOH, HAC-F, and Belimo actuator HAC models with end switch option
End switch requirement depends on model. Combustion air proving models and end-switch proving models use the end switch signal to confirm the blade has physically reached its open position before allowing the appliance or exhaust fan to activate. Without it, the interlock sequence cannot complete. Simultaneous models activate all outputs at once and do not require an end switch. For combustion air models: the HOM SF1 and SF2 include the end switch. For proving models using HAC: order SPO or SPC. For simultaneous models using HAC (ADP-0241-05A, ADP-0242-05A): order OPO or OPC. See the compatibility table on this page to confirm requirements for your model.
| Model | Application | Voltage | Key Detail |
|---|---|---|---|
| ADP-0MV2-S5A | Combustion air: gas furnace with standing pilot / thermopile / thermocouple safety system | Millivolt 250mVdc–100Vdc | 2 relays + test/run switch; the only ADP model for millivolt safety circuits; use HOM SF1 or SF2 |
| ADP-0241-10A | 24 Vac ventilation switch, 120 Vac fan load up to 10A | 24 Vac | Same application as ADP-0241-05A with 10A contacts for switching a 120 Vac fan. Not used for HOM combustion air: on a 24 Vac appliance the HOM wires directly to the thermostat circuit |
| ADP-0241-05A | Fresh air damper + furnace fan: ventilation code compliance | 24 Vac | Ventilation switch simultaneously opens HAC fresh air damper and activates furnace fan, no end switch required; order HAC OPO or OPC |
| ADP-1102-S5A | Combustion air: boiler or tankless water heater | 110 Vac | 5A relay output: standard residential boilers and tankless units; use HOM SF1 or SF2; confirm load rating on appliance spec label |
| ADP-1102-10A | Combustion air: boiler or tankless water heater (higher load) | 110 Vac | 10A relay output: larger commercial-grade boilers and tankless units; use HOM SF1 or SF2; confirm load rating on appliance spec label |
| ADP-0242-05A | Exhaust fan switch → fresh air damper + furnace fan simultaneously; damper also opens during furnace firing | 24 Vac | 2 relays (24Vac coil): simultaneous operation; second relay opens damper during furnace firing; no end switch required; order HAC OPO or OPC |
| ADP-1101-10AS | Two 110 Vac exhaust fans: non-concurrent; furnace fan + fresh air damper for either fan | 110 Vac | Prevents fans running simultaneously; furnace fan + damper activate for whichever fan is on; requires ADP-1101-05A or ADP-1102-TWP companion adaptor |
| ADP-0244-05A | Two-zone furnace fan control: special order | 24 Vac | Manages fan sequencing for two independent zone damper circuits: special order; confirm lead time with wholesaler |
Models
24 total, 8 primary shown
Voltages Covered
Millivolt, 24 Vac, 110 Vac
Relays
Up to 4: field-replaceable
Wiring Diagrams
Colour: included in every box
A/C Circuit
Not affected: all models
End Switch
Depends on model: see table
Millivolt furnace (standing pilot)? Order ADP-0MV2-S5A: the only model in the series rated for millivolt safety circuits. Standard 24 Vac models will not work. For fresh air damper + furnace fan (ventilation code compliance) order ADP-0241-05A with a HAC OPO or OPC variant, no end switch required. For combustion air on a 24 Vac furnace, no adaptor is needed: the HOM SF1 or SF2 wires directly into the thermostat circuit.
Pre-engineered interlock, relays field-replaceable
Made in Canada · Colour wiring diagrams included · A/C circuit not affected
Product image is representative only. Actual product may differ in appearance depending on size, configuration, and options selected at order.
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