Great care must be taken to ensure that the thread of cable glands, or conduit, matches its corresponding thread
so that the entire installation achieves the level of protection required. Long cased, fully ducted fans fitted with
ENV89 motors are not fitted with an external terminal box. The supply cable to the motor terminal box must be
fed through the conduit hole in the fan duct and connected into the terminal box before the fan is fully installed
(i.e. before the inlet and outlet ducts are fitted).
Any electrical control gear (including the capacitor in the case of single-phase motors) must be located outside
the hazardous area if it is not certified for use in that zone. The motor should not be allowed to become coated
with dirt/dust, etc. which could restrict surface cooling and consequently raise the temperature of the motor
carcase.
5.7 SWITCH ON
Before switching on, confirm that the electrical supply is fully compliant with the requirement of the motor as
detailed on the motor nameplate, that the fan is correctly installed, all component parts and fixings are secure,
safety guards are in place and no loose articles are present in the vicinity.
Immediately after switch-on check for the correct direction of rotation. If the rotation is incorrect interchange any
two phases of the incoming supply at the motor terminal block, to rectify this for three phase motors.
For single-phase motors, the motor winding leads should be interchanged at the motor terminal block. In the
case of BT and CT motors, these are identified by black and red coloured wires. In the case of other motors these
wires are labelled “U1” and “U2”.
Check the assembly for smooth, low-vibration running, and check that the current consumption is within the full
load current specified on the nameplate. The fan must not be switched on and off in a manner that could cause
overheating of the motor or its wiring.
6. MAINTENANCE
ATTENTION!
No maintenance work should be attempted before switching off and completely isolating the fan
assembly, its anti-condensation heater (If fitted), and its controls, from all electrical supplies and
allowing the rotating parts of the fan to come to rest.
ATTENTION!
Before entering the area ensure that all fumes, dust, toxic emission, heat etc. have dispersed from the
local environment, and the fan blades are not likely to windmill.
ATTENTION!
All lifting aids used during maintenance, and all lifting points utilised, should be adequately certified to
carry the weight of the equipment being lifted. (See paragraph 4).
ATTENTION!
Always wear appropriate protective clothing (including hard hats, eye protectors and ear defenders) when
working in the vicinity of the fan assembly.
Maintenance must be carried out on the fan assembly by appropriately qualified personnel using the correct tools
and equipment. A regular routine maintenance schedule should be established, and a record kept. A list of
suggested intervals are given in Table 1.
Where the environment is particularly dirty, a reduction in the intervals may be necessary. Internal and external
fan surfaces may be cleaned with low pressure clean water and non-abrasive additives. Direct application of
water from any direction to the motor drain plugs must be avoided.
After maintenance ensure that no loose articles are present in the vicinity of the fan, that all safety guards,
chains or steel ropes, etc., are properly secured into their original location, and that any temporary device used
to stop the fan blades windmilling has been removed.
6.1 FIXINGS
It is essential to ensure that all fixings on the fan assembly are secure. When examining and checking the
security of fixings during routine maintenance (see Table 1 Items 10 and 11), those fixings that have locking
devices fitted or are painted over, need not be disturbed if they can be seen to be secure. Any locking devices
that are disturbed during maintenance must be discarded and replaced with new identical devices.
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