E N
EN - 11
NA 03.28 D
Retighten the connections after 48 hours of operation.
A suitable air flow rate controller (pressure switch, switch indicator, etc.) must be placed in the circuit to shut off power to the heaters
should an air flow fault occur.
CIAT shall not be liable if this requirement is not followed.
Never operate the coil with the fan off.
For the variable-speed motors, the power dissipated by the coil must be proportional to the motor rotation speed and adjusted gradually.
For a two-speed motor, the control system is configured so that the reduction in the air flow results in a proportional reduction in the
heater power.
For example: 1500 / 750 rpm, coil capacity of 30 kW.
At low speed, the power dissipated by the heater must be reduced by 50% and not exceed 15 kW.
A number of factors can cause general overheating of the electrical elements, which can lead to the thermostats being triggered:
Examples:
- turning on the unit without the fan,
- filter fouling,
- reversed fan rotation,
- faulty operation of the air dampers,
- insufficient voltage to the fan motor assembly belt.
3.6 Control system
If the air intake is fitted with a motorised damper, the fan should not operate unless the opening limit switch is tripped.
If a two-speed motor is used, the shift from high to low speed should be timed to avoid a braking effect.
3.7 Fan motor assembly
The spring-mounted fan motor assemblies (AIRTECH, AIRCLEAN ranges) are locked in place during shipment by three fasteners placed
on either side of the support frame.
Remove the shims after installing the unit.
The direction of rotation must match that indicated on the fan.
In most cases the drive is fitted before leaving the factory. All that needs to be done is to retension
the belts after 24 hours of operation. The tension depends on the belt type, the power to be
transmitted and the rotation speed.
Overtensioning the belts will result in accelerated wear of the bearings. Undertensioning the
belts will cause them to slip and wear down.
Place two strips of opaque adhesive tape exactly 250 mm from each other.
Gradually tighten the belt in successive increments until the gap between the two adhesive tapes reaches:
an extension of 0.4% to 0.6%, (0.4% = 251mm and 0.6% = 251.5mm).
Do not use the existing marks on the belts as a reference.
Tension the belts as shown in the photos below:
If the drive and/or motor is to be delivered later, proceed as follows:
- Clean the shafts and keys,
- Select the corresponding pulley,
- Insert the pulleys or the bushes,
- Align the pulleys.
