- 16 - - 17 -
4) Re-insert connector into the correct location on the control board and
route the cable to the back of the APU Midi and secure with a cable tie to
the retainer.
5.26 Supply cord replacement:
The supply cord and internal wiring within the terminal box are routed
and secured to ensure compliance with the electrical standard EN
60335-1. It is essential that prior to any disturbance of this internal
wiring, all cable routing and securing details are carefully noted to
ensure re-assembly to the same factory pattern is always maintained.
If the supply cord is to be changed or is damaged, it must be replaced
with a special cord assembly available from ADEY or one of their
approved repairers.
On disassembly note the cord retention and routing system.
Re-assemble to the same pattern. For information on cable connection
consult the wiring diagram.
Model Fuse Size (AMPS)
All models 5
5.24 RS 485 Modbus – BMS Connection:
RS 485 is available on this product for BMS connection and is enabled in the
Advanced settings menu.
5.25 Fuses: The following fuse size should be used:
The APU Midi is fitted with an internal re-settable fuse, see Section 11.
6 COMMISSIONING
6.11 Pre-commissioning checklist:
Before starting the commissioning process the following conditions must be met.
If these conditions are not adhered to, damage to the equipment, system and
property may result.
zEnsure the unit is sited in a frost free area, away from precipitation and
water sprays/jets.
zAll necessary pipe/electrical connections should have been made to a
satisfactory standard by a qualified person.
zThe temperature and pressure at the point of connection are within the
operating limits of the pressurisation unit.
zThe heating/cooling system is fitted with a safety valve and expansion
vessel sized appropriately.
6.12 In order for the pressurisation unit and heating/cooling system to function
correctly the following conditions must be met. If these conditions have not
been met, the commissioning process should not continue.
zEnsure the system connection has been made into the heating/chiller
system return header.
zEnsure non-return valves, pressure reducing valves or RPZ valves are NOT
installed between the pressurisation unit and the heating/cooling system.
zThe expansion vessel is pre-charged to the correct pressure (equal to
initial system design pressure).
6.13 Prior to commissioning fill the heating/cooling system via a filling loop if
possible. If this is not possible, the pressurisation unit can be used to fill the
system after commissioning has taken place. Depending on the size of the
system, this may take a considerable amount of time. The system fill
function of the unit will stop after 24 hours, if further filling is required,
reset this function.
zEnsure the heating/cooling system is filled and pressurised to the required
cold fill pressure, with the water at approximately ambient temperature.
zEnsure the system is dosed with a suitable corrosion inhibitor. Note the
APU Midi is not designed for dosing chemicals into the system, this must
be done via other means.
6.14 Expansion vessel setting:
zTo set or check the expansion vessel charge pressure the lock-shield
valve between the APU Midi and the vessel must be closed and the
vessel drained using the drain valve.
zA suitable gauge should be used to check the charge pressure.
zIf the charge pressure is too high it can be reduced by releasing air from
the vessel pre-charge valve or by using a pressure gauge with an integral
air release valve.
zIf the charge pressure is too low a small increase can be provided using a
car foot pump otherwise an oil free compressor or nitrogen bottle is
recommended.
zWhen the correct pressure is set the Schrader valve protective cap must
be replaced.
zCheck the integrity of the pipe-work. Ensure the lock-shield valve
between the system and the expansion vessel is open and the drain
valve is closed.
Fig. 19
Retainer
Cable tie
