Brand: ABB
Category: Other
Document Type: Manual
Language: EN
Manual for HMB-8 / HMB-11
Uploaded: April 20, 2026, 8:01 p.m.
Warranty Information
Copyright 2003, 2005 ABB All rights reserved.
The HMB mechanism is a compact, hydraulically-operated device that uses a disc spring assembly for energy storage. It receives signals from an electrical control system and uses pilot valves to generate mechanical motion for opening and closing circuit breaker contacts. A hydraulic pump compresses oil to charge the disc spring assembly, with a limit switch assembly monitoring spring compression to control the pump motor. The mechanism operates by releasing stored energy from the disc springs to move a drive piston. It includes various hydraulic elements such as a pump, accumulator pistons, pilot valves, and a changeover valve. Maintenance procedures cover checking oil levels, draining oil, replacing components, and leak checking the system. Manual operation is possible under specific conditions, and troubleshooting guidance is provided for common problems.
Troubleshooting and error codes
| Problem | Cause | Action |
|---|---|---|
| Drive is not charged automatically | Defective Limit Switch | Replace switch |
| Motor Supply Disconnect open | Close the disconnect | |
| No supply voltage | Turn on the supply voltage | |
| Defective pump motor | Replace the pump motor as per section 4.3.7 | |
| Motor is running, but the spring is not charged | Worn carbon brushes | Replace the carbon brushes |
| Pressure relief valve handle is open | Close the pressure relief (rotate handle) against the mechanism body | |
| Defective pump element | Replace the pump element as per section 4.3.3.1 | |
| Low oil level | Add hydraulic oil as per section 4.3.6.1 | |
| Oil leaking | Locate and correct leak area | |
| Drive fails to trip | Air in pump element | Perform vacuum procedure as per section 4.3.5 |
| No tripping voltage | Turn the voltage on | |
| Corrosion in drive | Defective coil | Replace the coil |
| Auxiliary switch not working | Re-adjust the switch to pass on the command | |
| Drive covers are not tight | Dirt in oil | Remove, filter and reinstall oil |
| Disconnect for anti-condensation heater open | Close the disconnect | |
| No supply voltage for the anti-condensation heater | Turn on the supply voltage | |
| Excessive pump runs; drive charges too frequently | Defective anti-condensation heater | Replace the old anti-condensation heater with a new one |
| Drive covers are not tight | Replace drive cover gaskets | |
| Erratic breaker speed | Internal leaking or dirt | Contact ABB Service. Field repair is possible with training or guidance |
| Defective seal | Replace appropriate seal | |
| Trapped air pockets | Perform a vacuum procedure on oil reservoir as per section 4.3.5 |