The MGT is the worm gear trolley: gear head reduction rather than belt and chain, with a drum-band solenoid brake, on a ceiling trolley mount. It is what you specify when an OTBH is not enough operator for the door.
What This Operator Suits
Industrial standard lift sectional doors that are too heavy or too hard-worked for the OTBH class.
Worm gear reduction delivers torque consistently under sustained load and removes the belt tension maintenance a V-belt drive needs. On a trolley mount, that combination suits big industrial sectional doors where a jackshaft is not an option because there is no shaft to drive.
Specification
| Item | Detail |
|---|---|
| Motor | Heavy-duty worm gear industrial, continuous-duty |
| Reduction | Worm gear reducer |
| Brake | Electrically activated drum-band solenoid brake |
| Manual operation | Manual chain hoist / disconnect per configuration |
| Control board | BOARD 070, monitored entrapment protection, ANSI/CAN/UL 325 compliant |
Duty rating in plain terms. Heavy-duty industrial trolley.
What Fails on This Unit
Gear reducer oil and the solenoid brake are the two maintenance points. On a trolley, add track alignment, a long trolley track that has sagged or shifted binds the carriage, and on a gear head unit with plenty of torque the operator will keep pulling against the bind until something breaks rather than stalling out.
Manufacturer Documents
Originals from Manaras-Opera, useful if the paperwork for a unit already in your building has gone missing:
Choosing Between Models
The OTBH is the belt-and-chain trolley below it; MGH the jackshaft equivalent. If you are unsure which unit you have, the model code is on the data plate on the operator housing. Note the voltage and phase while you are there, and roughly how many cycles a day the door runs, those three facts decide most of what we would bring to a call.
See the full Manaras model reference for the whole range, or Manaras operator repair for service.
Parts and Accessories
Manaras publish a full accessory range that pairs with this operator: monitored and non-monitored photoelectric cells, light curtains, electric and pneumatic sensing edges, interface modules, push-button and key switch control stations, pull switches, keypads and card readers, radio receivers and transmitters, and traffic light kits.
One point that causes repeated confusion: on a UL 325 monitored circuit, a failed safety device makes the operator refuse to close. That is correct behaviour, not a malfunction. A door that suddenly will not close, with no other symptom, is very often a photo eye or sensing edge that has failed or drifted out of alignment.
- Accessory catalogue (PDF)
- Accessories and replacement components list (PDF)
- Radio Series 900 dip-switch compatibility chart (PDF)
- Radio Series 100 rolling code compatibility chart (PDF)
- Operator codes explained (PDF)
We stock the common wear items for the Opera and MEGA series, control boards, clutches, solenoid coils, limit switch assemblies and safety edges. Anything we do not carry we source through our distributor, and you will hear about a lead time before we attend rather than after.
Frequently Asked Questions
How do I confirm I have a MGT?
The model code is on the data plate on the operator housing. If the plate is unreadable, which happens on older units in damp parkades, send us a photo of the operator and we can usually identify it from the frame and drive layout.
Do you stock parts for it?
We carry the common wear parts across the Opera and MEGA series. Model-specific components come through our distributor, typically within two business days.
Is it worth repairing or should we replace it?
Clutches, brakes, boards, limits, safety devices and wiring are repairs. A seized gear reducer or a burnt-out motor on a very old unit is usually a replacement. We tell you which one you are looking at and why, rather than leading with a new-operator quote.
Can you service a unit we did not buy from you?
Yes. Most Manaras units we attend were installed by someone else, often years ago.
The door will not close but opens fine. Is the operator dead?
Almost certainly not. That is the classic monitored safety circuit symptom, a photo eye, light curtain or sensing edge that has failed or moved. Check the lenses are clean, the alignment is good, and nothing is parked in the beam before assuming the worst.