Brand: ABB
Category: Drives
Document Type: Manual
Language: EN
Manual for DMI
Uploaded: April 20, 2026, 7:58 p.m.
DC Machines DMI - Operating and Maintenance Instructions
Safety Instructions:
- Operate only by skilled personnel.
- Machines have rotating parts and may be live.
- Follow national and local regulations.
- Intended for industrial and commercial installations.
- Prohibited in hazardous areas unless specified.
- Consider ambient temperature and altitude limits.
- Report transport damage immediately.
- Ensure proper support and alignment during installation.
- Avoid resonances and obstructions to ventilation.
- Electrical connections must be permanent and safe.
- Maintain clearances between live parts and earth.
- Operation without excitation can lead to overspeeding.
- Switch off if deviations occur (temperature, noise, vibrations).
Machine Description:
- Technical data is on the rating plate.
- Key parameters include type, standard, thermal class, supply, weight, duty cycle, cooling, protection, ambient conditions, and excitation.
- Detailed part descriptions are provided with diagrams.
General Storage Precautions:
- Avoid condensation, corrosive gases, and vibrations.
- Lift brushes and wrap commutator.
- Store in a dry, dust-free, low-vibration environment.
- Maintain a constant temperature, at least 5 K above ambient.
- Store in a gas-free room.
- Shaft extensions have anti-corrosion coating.
Foundation:
- Foundation must be strong and stable.
- Avoid resonances.
- Mounting area must be level and vibration-free.
- Use shrink-free concrete for grouting.
- Ensure no air pockets in concrete.
Machine Installation:
- Perform checks before starting installation.
- Ensure site is clean and prepared.
- Use proper lifting eyes.
- Connect using flexible couplings.
- Ensure proper alignment (parallel and angular).
- Follow V-belt drive arrangement guidelines.
- Observe tightening torques for foundation bolts.
- Connect cables according to terminal diagrams.
Commissioning:
- Check armature rotation, couplings, cooling air, and fan direction.
- Ensure electrical connections are tight.
- Verify protective equipment is functioning.
- Measure insulation resistance.
- Check bearings are greased.
- Monitor bearing temperatures and vibrations.
- Inspect commutator and brushes after 100 hours.
Observation and Maintenance:
- Regular maintenance prevents failures.
- Monthly checks: brushes, commutator, commutation, vibrations, bearing conditions, thermostat functions, air filters.
- Every 4 months: clean inside motor, measure insulation resistance, inspect connections.
Insulation Resistance:
- Measure with a 500 V megger.
- Recalculate to 40 °C using correction factors.
Brushes and Commutation:
- Good commutation depends on air humidity, temperature, and brush grade.
- Patina formation is crucial for protection.
- Sparking indicates poor brush contact or other issues.
- Address poor brush contact causes like vibrations, low load, humidity, or corrosive environments.
- Replace worn brushes as a set and bed them in properly.
Heat Exchangers:
- Ensure proper water supply and pressure tests.
- Evacuate air from the system.
- Regulate water flow and avoid erosion.
- Check gaskets and filters.
- Verify monitoring equipment functionality (filter monitor, pressure switch, thermostat, etc.).
- Perform regular maintenance on motors and heat exchangers.
Dismantling and Reassembling:
- Ensure electrical disconnection before dismantling.
- Follow step-by-step instructions for removal and reassembly.
- Pay attention to gasket condition and cleanliness of mating surfaces.
- Fill bearings with grease during assembly.
- Observe tightening torques for stator bolts.
Spare Parts:
- Recommended spare parts list provided based on the number of identical motors.
- State motor type, serial number, and part number when ordering.
Faults and Remedies:
- Mechanical: Rough running, bearing issues (overheating, noises, indentations).
- Electrical: Motor not starting, not accepting load, overspeeding, generator issues, overheating.
- Commutation: Sparking (leading/trailing edge, showers, arc), brush wear, uneven wear, commutator wear, metal particles, stains.
EC Directives:
- Declaration of Incorporation and EC Declaration of Conformity provided.
Troubleshooting and error codes
| Mechanical | Fault | Possible cause | Remedy |
|---|---|---|---|
| Rough running | When coupled, machine runs unevenly or with strong vibration, with no fault when uncoupled | Fault in power transmission components or in driven equipment | Check power transmission, drive components and alignment |
| Settling of foundation | Restore correct foundation level, realign machine set | ||
| Machine runs roughly when uncoupled | Transmission or driven equipment badly balanced | Rebalance | |
| Bearing damage | Refer to bearing faults below | ||
| Holding-down bolts loose | Tighten and lock | ||
| Post-mounted coupling adversely affecting rotor balance | Rebalance rotor with coupling | ||
| Damage to rolling bearings | Overheating immediately after starting or regreasing | Too much grease filled | Fill and press in only the prescribed amount of grease (See rating plate). Overheating automatically disappears after some time |
| Overheating after long period of operation | Bearing cover seals rubbing | Remachine bearing cover, replace damaged seals | |
| Scraping, rubbing or knocking noises in bearing | Bearing is dry | Change bearing (cause to be determined by specialists) | |
| Whistling sounds in grease lubricated bearings | Damage on bearing cage | Inject grease | |
| Formation of indentations | When machine stationary | Vibrations being transferred to bearings from external source | Replace bearing |
| When machine in operation | Electric current flowing through the bearing | Isolate motor from external vibration or keep rotor turning continuously Consult ABB |
| Electrical | Fault | Possible cause | Remedy |
|---|---|---|---|
| Motor will not start at no load | No armature voltage | Check supply | Check supply |
| Armature coils burnt out or short-circuited | Clear short-circuit (generally only possible in specialist's or manufacturer's workshop) | Clear short-circuit (generally only possible in specialist's or manufacturer's workshop) | |
| Brushes not making proper contact | Check pressure and position of brushes, replace worn brushes | Check pressure and position of brushes, replace worn brushes | |
| No excitation voltage | Check supply | Check supply | |
| Open circuit in field winding | Remedy open circuit | Remedy open circuit | |
| Interturn short-circuit in the armature winding | Repair in workshop | Repair in workshop | |
| Short-circuit between commutator segments | Check commutator and eliminate short | Check commutator and eliminate short | |
| Motor will not accept load | Overload | Check current input and eliminate overload | Check current input and eliminate overload |
| Voltage decreasing | Check supply | Check supply | |
| Motor overspeeding and hunting under load | Brushes displaced from neutral zone in opposite direction to rotation position | Set brush-bracket to mark under load | Set brush-bracket to mark under load |
| Fault in field circuit | Eliminate fault | Eliminate fault | |
| Auxiliary series winding wrongly connected | Check connection and correct | Check connection and correct | |
| Generator not supplying voltage | Open circuit in excitation circuit | Check excitation circuit for fault | Check excitation circuit for fault |
| Short in main circuit | Check circuit | Check circuit | |
| Open circuit or interturn short-circuit in rotor winding | Check winding for open circuit or interturn short-circuit | Check winding for open circuit or interturn short-circuit | |
| Speed reduction of drive too great | Set drive to normal speed, drive too weak | Set drive to normal speed, drive too weak | |
| Overheating in operation | Incorrect brush setting | Check brush setting, correct | Check brush setting, correct |
| Overload | Check voltage and current, eliminate overload | Check voltage and current, eliminate overload | |
| Insufficient cooling air | Improve cooling | Improve cooling | |
| Temperature of cooling air or water too high | Clean internal and external air passages | Clean internal and external air passages | |
| Insufficient cooling water | Check flow rate of cooling water, increase if necessary | Check flow rate of cooling water, increase if necessary | |
| Cooler or filter dirty | Clean cooler, change filter | Clean cooler, change filter |
| Commutation | Type of fault | Causes and remedies | |
|---|---|---|---|
| Brush sparking | Brush sparking at the leading edge | 1 4 8 9 10 38 39 | Reset neutral position |
| Brush sparking at the trailing edge | 1 3 22 24 37 38 39 | Correct the distance between the studs | |
| Slight sparking | 1 3 4 6 8 9 14 19 22 24 28 29 33 39 | Increase commutating pole air gap | |
| Violent sparking with showers | 6 8 9 10 13 31 32 34 35 36 37 | Decrease commutating pole air gap | |
| Arc or flash | 1 10 22 26 35 | Use suitable brushes, reduce the number of brushes | |
| Sparking of some brushes or sets of brushes | 2 6 7 9 14 19 20 24 25 27 28 29 31 32 33 36 37 | Clean the commutator and identify cause | |
| Burning of the rear corner of the brushes | 1 4 14 19 27 29 30 32 35 37 | Remove the brushes and brush them clean | |
| Vibration and breaking of the brush edges | 5 12 14 23 24 25 30 32 33 36 37 | Reduce the load | |
| Brushes wear out too fast | 6 7 8 9 12 15 16 22 23 27 30 31 32 33 37 38 39 | Check the alignment, rebalance if necessary | |
| Uneven brush wear | 2 6 7 12 16 20 24 27 29 30 31 32 34 37 | Repair, rewind if necessary | |
| Plait interruptions and burning | 2 6 8 10 11 16 17 18 20 23 31 35 | Trace the causes, then consult ABB if necessary | |
| Grooves on the brush sides | 16 25 | Reduce the number of brushes | |
| Grooves on the brush surfaces | Grooves on the surfaces of contact | 6 8 17 | Choose suitable brush types |
| Metal particles on the surfaces of contact | 14 17 20 21 | Let in fresh air, select suitable brushes | |
| Uneven commutator wear | 6 11 12 15 17 18 20 23 38 39 | Let in fresh air, select suitable brushes | |
| Grooves on the commutator surface | 6 12 14 15 16 17 18 20 24 27 30 33 | Fit filters and eliminate the causes | |
| Symmetrical stains on the commutator | 1 10 13 21 28 35 | Let in fresh air, select suitable brushes | |
| Asymmetrical stains on the commutator | 20 34 36 37 | Reduce brush pressure, make use of non-abrasive brushes | |
| Scored commutator surface | 6 7 12 14 16 17 19 24 27 30 38 39 | Adapt the brushes perfectly, as previously shown | |
| Protruding commutator segments | 37 | Use brushes of the same type | |
| Broken soldering | 35 | Raise the brushes | |
| Scored commutator | 20 34 36 37 | Replace the brush spring and brush presser pad |