Electric Heaters; Cooling Coil; Heat Recovery Wheel; Plate Heat Exchanger - Carrier AiroVision 39 HQM Advance Installation, Operation And Maintenance

Central station air handling units
Table of Contents

Advertisement

5.4 – Electric Heaters
- Ensure that the heater has been connected in
accordance with the instructions of the supplier. The
diagram is located on the inside of the connection
module.
- Check the heater current.
- Check if the safety devices shown in the wiring
diagram have been installed.
- Check if the heater has been earthed in accordance
with local instructions.
- The electric heater will be switched on if there is no
air flow rate across the heater exists.
- Ensure that no objects have been left in the heater
section.
- The following warning labels are attached to the
panel: electrical voltage and hot surface.
5.5 – Cooling Coil
When calculating trap depth on draw-thru or blow-thru
applications, remember that it is not the total static
pressure but the upstream or downstream static
resistance that is trapped against.
When calculating the trap depth for a cooling coil
condensate pan on the draw-thru side, trap against the
coil pressure drop in that coil section and any other
pressure drops upstream of it (Negative Static
Pressure).
NSP = Negative Static Pressure
(in Pa)
L = Overall trap height
A = (NSP/250*25.4) + 50 (mm)
B = NSP
L = A + B + Pipe diameter
Condensate Drain, Draw-Thru Trapping
To determine the trap dimensions for blow-thru units,
find the coils maximum positive pressure and add 1/2
inch. This figure is normally the fan total static
pressure.
TSP = Total Static Pressure
(in Pa)
A = 50 mm (minimum)
B = (TSP/250*25.4) + 50 (mm)
L = A + B + Pipe diameter
Condensate Drain, Blow-Thru Trapping
- Check the connections in accordance with the
dimensional drawing.
- Control the connections for leaks.
- Check U- trap dimension according to above details.
- Insure no damage in fins. Correctly straighten the fins
- After several days of cooling operation check the
condensate drain and operation of the U trap, if
necessary clean it.

5.6 - Heat Recovery Wheel

- Check that the wheel is rotating in the correct
direction. This is indicated by an arrow on the casing.
- Check if the wheel seals are fitting correctly.
- Check if belt tension is correct.
- Check if the motor has been correctly connected.
- Check if the controller has been correctly connected
and set in accordance with the instructions of the
supplier if any.
- Check if the rotor speed has been set correctly.
- The following warning label is attached to the panel:
rotating parts.

5.7 - Plate Heat Exchanger

Used if dampers are installed.
- Check if the actuator motor has been installed in
accordance with the instructions of the supplier.
- Check if the correct angle has been set.
- Check if the dampers close correctly.
- Check if the damper can open to the correct position.
- Check operation after the power has been restored
following a power cut. Some dampers must be open,
others must be closed.
- Insure no damage in fins. Correctly straighten the
fins.
5.8 – Fan and Motor
- Remove the transport brackets. This is indicated by a
label on the fan access door.
- Untighten spring isolator bolt
- Check if the fan can move freely without obstructing
the frame, flexible connection or wiring.
- Insure power connection is star / Delta for motors
above 5.5 kW
- Check and/or connect the motor in accordance with
local instructions and the data of the supplier.
- Check the direction of rotation of the impeller. The
direction is indicated on the fan casing by an arrow.
- Separately measure the current draw of the electric
motor for all phases. The current draw of all phases
must be approximately the same and agree with the
10

Hide quick links:

Advertisement

Table of Contents
loading

Table of Contents