Floating Point · 3-Wire · No Spring Return · Line Voltage
HAC-35
HAC-35
Belimo CMB120-3
Inline Damper
3-Wire Open / Stop / Close · 100–230 Vac · DDC Floating Point · 6"–20"
- ✓3-wire floating point — Open / Stop / Close incremental positioning
- ✓No spring return — holds last blade position on power loss
- ✓Line voltage supply: 100–230 Vac — no 24 Vac transformer required
- ✓End switch available on all sizes for BAS position confirmation
- ✓Heat bypass (−H) available on all sizes — confirm pricing with wholesaler
- ✓Same floating point architecture as HAC-34 (CMB24-3-T) — line voltage equivalent
- ✓Factory-mounted Belimo CMB120-3 — ships ready to install
Is this the right product?
✔ Right product if
Your DDC controller has a 3-wire floating point output (Open / Stop / Close), only line voltage (100–230 Vac) is available at the damper location, and no 24 Vac step-down transformer is installed.
✗ Not this product if
24 Vac available → use HAC-34 (CMB24-3-T) — same architecture, lower voltage.
On/off at line voltage → use HAC-44 (TFB120)
Spring return fail-safe required → CMB120-3 holds last position. Use HAC-44 (on/off spring return).
On/off at line voltage → use HAC-44 (TFB120)
Spring return fail-safe required → CMB120-3 holds last position. Use HAC-44 (on/off spring return).
What It Does
3-wire Open / Stop / Close at line voltage. The line voltage equivalent of the HAC-34. Holds last position on power loss — no spring return.
NO SPRING RETURN — Blade Holds Last Position on Power Loss
The CMB120-3 has no spring return. On power loss the blade stays wherever it was — it does not move to a defined open or closed fail-safe position. If your application requires the damper to seal or open on power loss, use a spring return product: HAC-44 (TFB120) for on/off spring return at line voltage.
The HAC-35 pairs Hoyme's inline damper body with the Belimo CMB120-3 — the line voltage version of the CMB24-3-T used in the HAC-34. Same Open / Stop / Close 3-wire floating point control architecture. Same holds-last-position behavior on power loss. The distinction is supply voltage: the CMB120-3 operates directly from 100–230 Vac line voltage, eliminating the need for a 24 Vac step-down transformer at the damper location. When a 24 Vac circuit is not available and the DDC controller has floating point outputs, this is the product.
3-Wire Control — How It Works
OPEN
Energized → blade moves toward open while wire is energized
CLOSE
Energized → blade moves toward closed while wire is energized
STOP
Neither energized → blade holds current position
CMB120-3 vs. CMB24-3-T — voltage is the only difference: The CMB120-3 (HAC-35) and CMB24-3-T (HAC-34) share the same 3-wire floating point architecture, the same holds-last-position behavior, and the same Open/Stop/Close wiring logic. The only difference is supply voltage. If 24 Vac is available at the damper location, use the HAC-34. If only line voltage is available and no transformer is installed, use the HAC-35.
Belimo Series — Control Type Selector
All Belimo-actuated HAC variants on a single Hoyme inline damper body. Select by control type and voltage.
| Model | Actuator | Control Type | Voltage | Spring Return | Link |
|---|---|---|---|---|---|
| HAC-40 | TFB24 | On/Off | 24 Vac/dc | Yes | View |
| HAC-44 | TFB120 | On/Off | 100–240 Vac | Yes | View |
| HAC-43 | TFB24-SR-T | Modulating 2–10 VDC | 24 Vac/dc | Yes | View |
| HAC-60 | LMB24-SR-T | Modulating 2–10 VDC | 24 Vac/dc | No — holds last | View |
| HAC-34 | CMB24-3-T | Floating point 3-wire | 24 Vac/dc | No — holds last | View |
| HAC-30 | LMB24-3-T | Floating point 3-wire | 24 Vac/dc | No — holds last | View |
| HAC-35 ← You are here | CMB120-3 | Floating point 3-wire | 100–230 Vac | No — holds last | — |
| HAC-70 | LMX120-3 | Floating point 3-wire | 100–230 Vac | No — holds last | View |
| HAC-90 | FSLF24 US | Fire & Smoke (UL 555S) | 24 Vac | Yes | View |
| HAC-80 | FSLF120 US | Fire & Smoke (UL 555S) | 120 Vac | Yes | View |
Configuration Guide
Select size, end switch, and heat bypass. Confirm 3-wire terminal assignments with the DDC controls designer before wiring.
| Variant Code | End Switch | Heat Bypass | Part Number Example (10") |
|---|---|---|---|
| OPP | No end switch | No bypass | HAC-1035-OPP |
| OPP-H | No end switch | 10% bypass | HAC-1035-OPP-H |
| SPP | End switch included | No bypass | HAC-1035-SPP |
| SPP-H | End switch included | 10% bypass | HAC-1035-SPP-H |
−H Pricing Anomaly — Confirm Before Ordering: As with the HAC-34, the −H heat bypass variants may be priced differently than expected relative to the standard variants. Confirm with your wholesaler or Hoyme directly before ordering. Do not assume −H is always the add-on option.
−H Heat Bypass — Hot Air Zone Control Only: Do not specify −H on fresh air intake, make-up air, or ventilation applications. The 10% bypass allows continuous outdoor air infiltration when the damper is commanded closed. Specify −H only on hot air supply duct zone control applications.
Part Number Decoder
HAC-1435-SPP
HAC
Product family: universal inline air control damper
14
Size (2-digit): 06=6", 08=8", 10=10", 12=12", 14=14", 16=16", 18=18", 20=20"
35
Motor code: Belimo CMB120-3, 3-wire floating point, 100–230 Vac, no spring return
O / S
End switch: O = no end switch | S = end switch included
PP
Floating point action code for CMB120-3 3-wire architecture
-H
Optional: 10% heat bypass. Hot air zone control only. Confirm pricing with wholesaler.
Key Specs
Sizes
6", 8", 10", 12", 14", 16", 18", 20"
Actuator
Belimo CMB120-3
Control Wires
3-wire: Open / Stop / Close
Supply Voltage
100–230 Vac line voltage
Fail-Safe
Holds last position — no spring return
Transformer
Not required — direct line voltage
End Switch
Optional (S prefix)
Relay
Not available
Heat Bypass
Optional (−H) — confirm pricing
CSA Status
Confirm with Hoyme
Warranty
2-yr electrical / 10-yr mechanical
Common Questions from the Counter
Answers to what comes up most when specifying the HAC-35.
When do I use the HAC-35 instead of the HAC-34?
When only line voltage (100–230 Vac) is available at the damper location and no 24 Vac step-down transformer is installed. The HAC-34 (CMB24-3-T) and HAC-35 (CMB120-3) are identical in control architecture — both are 3-wire floating point, both hold last position on power loss. The only difference is supply voltage. If 24 Vac is available, use the HAC-34.
What happens to the blade on power loss?
The blade holds its last position. The CMB120-3 has no spring return — wherever the blade was when power went out is where it stays until power restores and the DDC sends a new positioning command. If the application requires the blade to move to a defined position on power loss, use a spring return product: HAC-44 (TFB120) provides on/off spring return at line voltage.
Does the HAC-35 need a transformer?
No. The CMB120-3 operates directly from 100–230 Vac line voltage — the transformer requirement of the 24 Vac products does not apply. The DDC floating point output card still needs to provide the Open/Close/Stop switching, but the actuator power supply is taken directly from line voltage at the installation location.
Why is the −H heat bypass variant priced differently at some sizes?
Same pricing anomaly pattern as the HAC-34 — confirm with your wholesaler or Hoyme before ordering. The −H suffix indicates the 10% heat bypass blade configuration. Do not assume −H is always the add-on option at a higher price — the difference may reflect a blade configuration rather than a conventional add-on structure.
Ready to Order
HAC-35 — Belimo CMB120-3 Inline Damper
Select your size, end switch (OPP/SPP), and heat bypass option — then add to cart. Confirm −H pricing with your wholesaler before ordering.
Configure & Order →
Size · End Switch · Heat Bypass
Need help specifying the HAC-35?
Technical support available through your Hoyme wholesaler or direct.