LiftMaster Mega Arm Tower (MAT) Manuals & Support

The LiftMaster Mega Arm Tower is a 24 VDC barrier gate operator in a full aluminum cabinet. It opens or closes in 2.5 seconds and is rated for 6,000 cycles per day.

It has built-in battery backup, magnetic limit sensing, soft start and stop and a breakaway arm mount. LiftMaster is phasing out the MAT in 2026, and the TECHNA barrier is the replacement.

Identify your model

MATDCBB3 is the Mega Arm Tower with the aluminum cabinet. MADCBB3 is the Mega Arm with a polyethylene cover. Both share one manual.

Key specs

Open / close time	2.5 seconds
Duty	Continuous, 6,000 cycles per day
Motor	24 VDC, 1/2 HP equivalent
Power	115 VAC or 230 VAC single phase
Arms	12 ft and 15 ft aluminum or 14 ft padded recommended; up to 17 ft
Gear reduction	60:1 worm gear in oil bath
Limits	Magnetic
Accessory power	24 VDC, 500 mA
UL 325 usage class	Class I, II, III and IV
Operating temperature	-4 to 140 °F; -40 °F with optional heater

Manuals and documents

Installation Manual

MA and MAT Installation Manual
24 pages View PDF: MA and MAT Installation Manual (opens in a new tab)
UN201 500W Heater Kit Instructions
1 page View PDF: UN201 500W Heater Kit Instructions (opens in a new tab)

Spec Sheet

MA / MAT Data Sheet
2021 · 2 pages View PDF: MA / MAT Data Sheet (opens in a new tab)
MA / MAT Spec Sheet
2 pages View PDF: MA / MAT Spec Sheet (opens in a new tab)

Troubleshooting

The board has LED indicators: D11 heartbeat, D12 battery status and D14 AC power.

Gate will not operate

No heartbeat: check the battery connections and fuse F4.
BAT LO on: restore AC power and let the batteries charge.
Shadow, safety, backaway or open input active: clear the input so the arm can close.

Battery check

Turn off AC and run 5 to 10 cycles. If D12 lights, the batteries are weak. Good batteries read about 24.5 VDC.
Charge voltage should be 27.5 VDC with the batteries disconnected.

Arm stops or reverses

If the IRD lights, check the arm is not binding, then adjust the IRD.
If the IRD flashes, the max run timer expired. Check the belt for slipping, then remove all power and reapply to reset.

Common questions

LiftMaster is phasing out the MAT in 2026. The TECHNA CBG, PBG and IBG barrier operators are the replacements.

No. Order the arm separately. The MAT takes aluminum arms up to 17 ft.

Turn off AC power and run 5 to 10 cycles while you watch LED D12. If it lights, replace the batteries.