First of all, I want to say that if you have a STANDARD frame THREE PHASE electric motor that is less than 7.5kw, then it is probably uneconomical to rewind. NON-STANDARD THREE PHASE electric motors are typically worth repairing, due to the high cost and long lead-times quoted in replacing with new. SINGLE PHASE electric motor repair costs do not meet this KW criteria, as a common fault is a capacitor issue, which are relatively cheap to repair.
So, what are the parts that fail in an electric motor? Most common is bearing failure, this can be detected before ultimate electric motor failure, by listening and feeling for vibrations in the motor whilst running. Electric Motor Condition Monitors / Sensors are also available to detect early bearing wear, so if you have an expensive and vital asset I would recommend installing such a system. The cost of a bearing change can be as little as £100 (2026), this covers labour and new bearings such as 6201 to 6206, this is dependent upon the fixings of the motor being easily removed etc, we sometimes need to cut off fixings etc, re-tap drill and supply new fixings. Larger bearings cost more, we have performed some bearing changes that cost in excess of £2,000 if the bearing is special.
As mentioned above, capacitor failure is common on SINGLE PHASE ELECTRIC MOTORS, a capacitor only repair can cost from £100 also, dependent upon the capacitor size, the capacitor can be found in the terminal box, if you open up the lid it is sometimes visually obvious your capacitor has blown, some SINGLE PHASE ELECTRIC MOTORS have two capacitors, a start and a run.
If you have been unlucky and motor has suffered a supply issue, or the bearings have collapsed, then typically the bearing debris enters the winding and blows the winding, in which case the rotor will need rewinding. Costs for rewinding an electric motor in the UK vary widely, but as a rule of thumb you should budget a minimum of £800 for a three phase electric motor of less than 3kw to repair and rewind, along with a rewind the bearings will be changed and motor refurbished with new oil seal etc. A 4kw to 7.5kw THREE PHASE ELECTRIC MOTOR could cost more than £1,000 to rewind, a 7.5kw to 22kw THREE PHASE ELECTRIC MOTOR could cost between £1,000 to £2,000 to rewind and refurbish.
I hope this brief summary helps you out, please free to call us on 01295 263161 for any advice relating to electric motor repairs, pump repairs, fan repairs, machine repairs or electrical installation issues.