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17.2 LUBRICATION
IIn addition to routine maintenance, motor bearings will, in the longer term, require attention. If motor bearings are greased
through extended lubricators, then the required quantity of grease must periodically be applied in accordance with
information stated on the fan or motor nameplate and/or as per any instructions provided. A fully compatible grease type must
be used, and it is essential that all traces of water and dirt are removed from around the grease points and that a clean grease
gun is used. It is only necessary to apply a small amount of pressure when injecting the specified quantity of grease
into the re-gearing point. If grease injection requires the maintenance engineer to apply a high pressure, then the cause should
be investigated. Grease points are generally located close to the fan housing-mounted terminal box. Where motors require
re-lubrication, a separate instruction is normally issued with each fan/motor configuration. This gives details of lubrication
intervals and well as the type and quantity of grease to be used.
If further details are required, Please contact Woods Air Movement USA directly.
17.3 INFREQUENT USE
If the fan assembly is used less frequently than once a month, or is designed for emergency-use only, the following additional
maintenance procedures must be carried out, and a record kept:
- Resistance of motor windings to earth, must be measured (at 500V dc) each month. If these readings are less than 10 MΩ
(Megaohm), the motor must be dried out in a warm airflow (typically at +104°F) and re-checked before running the motor.
- The fan should be operated between 15 and 30 minutes each month ensure that correct lubricant conditions are
maintained within the bearings (i.e. to prevent grease hardening).
- An 'emergency-use' system should be run continuously for a minimum of fifteen minutes each month. The test should
not only confirm that the fan operates correctly but must also ensure that the emergency use control system overrides all
other control devices (except where matched frequency converters are used) (see Paragraphs 1 to 11 and 16.4 for more
information).
- If space heaters / anti-condensation heaters are fitted, check each month that they automatically switch on (i.e. they are
drawing current) when the motor is switched off.
18. OVERHAUL / EXTENDED MAINTENANCE
Advice on motor overhaul procedures, bearing /seal replacement, motor replacement, motor rewinding, spare parts, condition
monitoring, vibration analysis, refurbishment, etc. is available from Woods Air Movement USA.
For emergency use fans, we recommend that motor shaft seals and bearings must be replaced after 20,000 hours or 5 years of
normal operation whichever occurs first.
After 40,000 hours of running, we strongly recommend that a qualified and competent electrician performs a motor "health
check" (as described within section 8, Fault finding) to determine the motor insulation condition.
Where the fan is to be used for an emergency (smoke extraction) operation, if motor insulation readings are less than 10 MΩ
(Megaohm), then to ensure that adequate insulation life is available should the fan be required for emergency operation, we
therefore recommend that the motor must be replaced with a new motor, which has been manufactured in accordance with
current requirements as stated within the EN12101-3 specification
NOTE!
When dealing with High Temperature Smoke Extract fans, only an authorized company may undertake the
maintenance. Failure to do so may invalidate our warranty. The motor manufacturer's specification sheets are
available through Woods Air Movement USA. After overhaul/extended maintenance the fan assembly must be
correctly installed back into its original position in accordance Paragraphs 12, 13, 14 and 15 of this document.
After conducting overhaul /extended maintenance the fan assembly must be correctly installed back into its original position
in accordance Paragraphs 12, 13, 14 and 15 of this document. For advice on "switching on" after maintenance, please refer to
paragraph 16.5.
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