Description
Product image is representative only. Actual product may differ in appearance depending on size, configuration, and options selected at order.
Hoyme inline damper body with Belimo CMB24-3-T 3-wire floating point actuator. Three control wires — Open, Stop, Close — give the DDC controller direct incremental blade positioning: energize Open to move the blade toward open, energize Close to move it toward closed, de-energize both to hold position. No spring return. Sizes 6"–20" in even-inch increments.
⚠ No Spring Return — Holds Last Position on Power Loss
The CMB24-3-T has no spring return. On power loss, the blade holds wherever it was — it does not move to a defined open or closed fail-safe position. If your application requires the damper to move to a defined position on power loss — to seal the duct on power interruption, or to guarantee ventilation continues regardless of electrical state — this is not the correct product. Use a spring return actuator: HAC-40 (TFB24) for on/off, or HAC-43 (TFB24-SR-T) for modulating.
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3-wire floating point — Open / Stop / Close — the DDC controller energizes Open or Close to move the blade incrementally; de-energizes both to hold current position; blade stays exactly where the DDC leaves it
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Belimo CMB24-3-T — factory-mounted to Hoyme damper body — single SKU, ready to install; actuator field-replaceable through Belimo distributors without disturbing duct connections
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24 Vac or 24 Vdc supply — either polarity on DC; compatible with BAS control power that outputs DC rather than AC
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End switch available on all sizes — confirms physical blade position back to BAS digital input; useful on floating point systems where the DDC infers position from pulse timing — end switch gives definitive confirmation when the blade reaches its travel limit
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Heat bypass (-H) available on all sizes — 10% bypass machined into blade at factory for hot air supply duct zone control; do not specify -H on fresh air, make-up air, or ventilation applications
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Need lighter-duty floating point at 24 Vac/dc? — see HAC-30 (LMB24-3-T) — same 3-wire architecture, lower torque rating; or HAC-35 (CMB120-3) for line voltage
Confirm 3-wire terminal assignments with the DDC controls designer before wiring. The CMB24-3-T uses an OPP action code — blade direction is controlled by which wire the DDC energizes, not by a factory PO/PC setting. Confirm Open, Close, and common terminal wiring against the DDC output card specification before installation.
| If your application needs… | Product | Actuator |
|---|---|---|
| 3-wire floating point DDC — 24 Vac/dc, holds last position | HAC-34 | CMB24-3-T — this product |
| 3-wire floating point DDC — 24 Vac/dc, lighter-duty torque | HAC-30 | LMB24-3-T |
| 3-wire floating point DDC — 100–230 Vac line voltage | HAC-35 | CMB120-3 |
| On/off 2-wire spring return gate — 24 Vac/dc | HAC-40 | TFB24 |
| Proportional 2–10 VDC — spring return fail-safe | HAC-43 | TFB24-SR-T |
| UL 555S fire and smoke rated, 24 Vac | HAC-90 | FSLF24 US |
Control Type
3-wire floating point — Open / Stop / Close
Fail-Safe
Holds last position — no spring return
Actuator
Belimo CMB24-3-T
Supply Voltage
24 Vac or 24 Vdc
Sizes
6"–20" even inches
End Switch
Optional (S prefix)
Heat Bypass (-H)
Available — confirm pricing with wholesaler
CSA Status
Confirm with Hoyme before ordering
Ordering the -H heat bypass variant? In the variant selector, -H variants are priced lower than the standard (non-bypass) variants at several sizes — which is unusual for an add-on option. Confirm the correct variant and pricing with your wholesaler or Hoyme directly before ordering. The -H suffix indicates the 10% heat bypass blade for hot air supply duct zone control. Do not specify -H on fresh air intake, make-up air, or ventilation applications — the bypass allows continuous outdoor air infiltration when the damper is commanded closed.
2-year electrical · 10-year mechanical warranty
Hoyme damper body — Made in Canada · Belimo CMB24-3-T field-replaceable through Belimo distributors