MRGH Models & Key Specifications
| Specification | Detail |
|---|---|
| Motor | 60 Hz high starting torque, continuous-duty industrial, 3-phase, totally enclosed (TEFC or TENV) |
| Reduction | 40:1 worm gear in oil bath reducer with air breather and sealed ball bearings |
| Output Shaft | 1-3/8" with 5/16" keyway, 43 rpm, supported by cast iron flanged pillow block bearings (one support at 2 HP, two at 3 HP and above); base plate included |
| Final Drive | #50, #60 or #80 roller chain and sprocket (sized to application) |
| Brake | Electrically activated drum-band solenoid brake (brake motor optional) |
| Manual Operation | Emergency chain hoist, floor-level engaging device with electrical cut-out; hoist right standard, field-movable to left |
| Limits | Rotary cam limits with Accu-cam one-hand adjustment |
| Enclosure | NEMA 1, simple slide-off cover |
| Control | Monitored control circuit, on-board radio receiver |
| Duty Rating | Very heavy-duty 3-phase gearhead jackshaft , the largest worm-gear unit in the Manaras range |
What the MRGH Is Built For
This operator is specified when the door exceeds the capacity of the standard heavy-duty MGH , multi-blade industrial rolling steel, oversized sectional doors, and large grilles on warehouse or works entrances. It requires a three-phase supply and is built for continuous-duty cycles on doors that are genuinely big and heavy.
What Fails & How We Repair It
The MRGH shares the two classic worm-gear maintenance points , reducer oil and the solenoid brake , but at a larger scale. The pillow block bearings supporting the output shaft are greaseable service items; on a door this size, a neglected bearing growls long before it seizes. The heavy final drive chain (#60 or #80 on bigger installs) demands regular tension and wear checks , a stretched chain on a 40:1 reducer doesn't slip cleanly, it accelerates sprocket wear.
Because these operators hang on high-tension, heavy doors, many "operator problems" we attend turn out to be door issues: worn springs, failing door bearings, or a door drifting out of balance until the operator is doing work the counterbalance should handle. We inspect the entire system, not just the gearhead.
Choosing Between Models
If you're unsure which unit you have, check the data plate on the operator housing for the model code, voltage, and phase. Note roughly how many cycles a day the door runs , those three facts decide most of what we bring to a service call. The MGH is the standard heavy-duty gearhead below the MRGH; the high-speed equivalent is the Rapido RGH. We can help confirm the right fit during a site visit.
Parts & Accessories
The MRGH pairs with the full Manaras accessory range: photo eyes, light curtains, sensing edges, radio controls, control stations, and traffic lights. 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 won't close, with no other symptom, is very often a photo eye or sensing edge issue.
Service Across Metro Vancouver
We supply, install, and repair MRGH operators from our Richmond base , covering Vancouver, Burnaby, Surrey, Delta, and the Greater Vancouver area. Whether it's a scheduled oil change, brake adjustment, chain and sprocket replacement, or diagnosing a door balance issue that's overloading the operator, we show up with the right parts and the right three-phase test gear.
Call 778-873-7282 or tap to dial for a quote or emergency service.
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