When an industrial motor fails, you have two basic choices: revise the existing motor or buy new. For powers above 22 kW the revision is often cheaper and much faster. This guide gives a decision tree and a concrete 55 kW cost comparison so you can make the right call.
Available from stock at Van Bodegraven. Stock in Dordrecht, Piraeus, Singapore and China; shaft, flange, terminal box and coating are adapted where needed in our own workshop. Typically delivered from stock within 1 to 5 working days.
What does an overhaul actually involve?
A complete overhaul in our workshop in Dordrecht includes:
- Mechanical disassembly: motor fully stripped, all parts marked and recorded.
- Electrical diagnosis: surge test, insulation measurement, continuity test on the old winding to determine whether rewinding is needed.
- Mechanical inspection: shaft measured for straightness (< 0.02 mm tolerance), lamination stacks inspected, bearing housings measured.
- Rewind if necessary: old winding removed, new copper wire to the original scheme, impregnated with class-F or class-H varnish, dried in our drying oven.
- New bearings: always replaced, usually SKF Explorer or NTN equivalent.
- New seals: V-ring, NilosRing or labyrinth seal depending on the motor.
- Blasting and painting: back to bare steel, then two-component industrial paint or, on request, marine C5-M coating to ISO 12944.
- Assembly and alignment: all components assembled, runout measured, fine-balanced.
- Testing and comprehensive test report: no-load test, load test on our motor test bench, vibration measurement, thermal test, insulation test at elevated voltage. You receive a very detailed test report with measurable deviations from the original factory specifications.
A "complete overhaul" at Van Bodegraven means the motor comes back electrically and mechanically as new, with the same warranty as a newly purchased motor.
Cost comparison: 55 kW, 4-pole, IE3
Suppose your 55 kW process motor has failed after 18 years of faithful service. There are three realistic options:
| Option | Initial cost | Delivery time | Warranty | Residual value after 10 years |
|---|---|---|---|---|
| New ABB M3BP 55 kW IE3 | €4,500 | 2–4 weeks factory, or direct from stock | 18 months after in-service | €250 scrap |
| New ABB M3BP 55 kW IE5 SynRM | €5,800 | 4–8 weeks | 18 months | €300 scrap |
| Dormot Renew 55 kW (revised as new) | €2,300 (from stock, complete unit) | Direct from stock | 12 months after in-service | €200 scrap |
| Overhaul own motor (without rewinding) | €2,500 (overhaul labour + bearings + seals) | 1–2 weeks | 12 months on work performed | €200 scrap |
On purchase price alone Renew or overhaul seems the clear winner. But including energy costs over 10 years (at 4,000 h/year, €0.15/kWh), the picture changes:
| Option | Efficiency | 10-year electricity costs | TCO (purchase + electricity − residual) |
|---|---|---|---|
| New IE3 | 93.0% | €265,900 | €268,850 |
| New IE5 (SynRM) | 94.3% | €262,250 | €267,750 |
| Dormot Renew (typical IE2/IE3) | ~92.0% | €268,770 | €269,970 |
| Overhaul own motor (orig. IE2) | ~91.5% | €270,240 | €271,690 |
Over 10 years the absolute cost difference is small, but with more running hours, a higher electricity price or a fleet of dozens of motors, percentage points add up. Renew has the advantage of immediate availability and lower initial cash flow, which is decisive in many project budgets.
When is overhaul clearly the better choice?
- Tight budget constraint on project cost centre: overhaul/Renew significantly reduces CAPEX.
- Time pressure: Renew is available from stock immediately; overhaul typically takes 1–2 weeks for standard motors if no rewinding is needed.
- Sustainability reporting: an overhauled motor has a 70% lower CO₂ footprint than new (less copper, steel, aluminium required).
- Exotic specifications: if the original motor is a rare type with a specific mounting or terminal box configuration, overhaul is faster than building a custom new motor.
- Vessel coming up for dry dock: for temporary use until the next docking period, Renew is an excellent choice.
When is new the better choice?
- Efficiency class upgrade is strategic: if you can upgrade from IE2 to IE4/IE5, that pays back the premium within 3–5 years.
- Remaining life of vessel/installation > 15 years: a new motor typically has 25+ years of service life.
- Critical essential service without redundancy: maximum reliability counts more than purchase cost.
- Specifications have been updated: EMC requirements, ATEX zone change, new class rules — a new motor meeting current standards is simpler.
- Original motor not repairable: frame cracked, laminations severely burnt, shaft beyond allowable straightening tolerance.
An overhauled 55 kW motor saves roughly 450 kg CO₂ in production footprint compared with new (less steel, copper and aluminium extraction plus transport from Asia). For companies with ESG or CSRD reporting obligations this is a measurable contribution to scope 3 reduction.
What you get with Dormot Renew
The Dormot Renew line is our solution for "as new" overhauled motors from frame 63 to 560. Wide stock immediately available from Dordrecht:
- Up to 60% below new price
- Class-certified for non-essential duty by BV, LR, DNV, ABS, RINA, ClassNK
- 12 months warranty after in-service
- Complete test report + bearing certificates
- IP55 standard, higher IP on request
- Marine C5-M coating on request
No rights can be derived from the delivery times, prices and technical specifications mentioned in this article. Contact us for a concrete quotation and current delivery status.
Not sure whether overhaul works for you?
Send your motor data (power, running hours, application, budget) and we make a concrete comparison between new and overhauled so you can make the best choice.