Tightening Torques - Riello NXHP Series Installation, Operation And Maintenance Instructions

5 -MAINTENANCE
Refrigerant circuit
■ Fully clean the air heat exchangers with a low-pressure jet and
a bio-degradable cleaner.
■ Check the unit operating parameters and compare them with
previous values.
■ Keep and maintain a maintenance sheet, attached to each
HVAC unit.
All these operations require strict observation of adequate
safety measures: individual protection garments, compliance
with all industry regulations, compliance with applicable local
regulations and using common sense.
5.1.3 - Level 3 (or higher) maintenance
The maintenance at this level requires specific skills/approval/
tools and know-how and only the manufacturer, his representative
or authorised agent are permitted to carry out these operations.
These maintenance operations concern for example:
■ A major component replacement (compressor, evaporator),
■ Any intervention on the refrigerant circuit (handling refrigerant),
■ Changing of parameters set at the factory (application change),
■ Removal or dismantling of the HVAC unit,
■ Any intervention due to a missed established maintenance
operation,
■ Any intervention covered by the warranty.
■ One to two leak checks per year with a certified leak detector
and carried out by a qualified person.
To reduce waste, the refrigerant and the oil must be transferred
in accordance with applicable regulations, using methods
that limit refrigerant leaks and pressure drops and with
materials that are suitable for the products.
Always note that any contact with refrigerant can lead to a
cold burn.
Any detected leaks must be repaired immediately.
Do not overfill cylinders (no more than 80% volume liquid
charge)
Do not exceed the maximum working pressure of the cylinder,
even temporarily. In case of decomissioning, recovered
refrigerant shall not be charged into another refrigerating
system unless it has been cleaned and checked.
The compressor oil that is recovered during maintenance
contains refrigerant and must be treated accordingly.
Refrigerant under pressure must not be purged to the open
air.
If a refrigerant circuit is opened, plug all openings, if the
operation takes up to one day, or for longer periods charge
the circuit with nitrogen.
If a fault exists that could compromise safety, then no
electrical supply shall be connected to the circuit until it is
repaired. Before recharging the system, it shall be pressure-
tested with the appropriate purging gas. A follow up leak test
shall be carried out prior to leaving the site. Always charge
the system with the refrigerant mass indicated on the
nameplate.
NOTE:
Prior to beginning work on systems containing flammable
refrigerants, safety checks are necessary to ensure that the
risk of ignition is minimised. For repair to the refrigerating
system, the following points shall be completed prior to
conducting work on the system.
Work shall be undertaken under a controlled procedure so
as to minimise the risk of a flammable gas or vapour being
present while the work is being performed.
All maintenance staff and others working in the local area
shall be instructed on the nature of work being carried out.
Work in confined spaces shall be avoided.
The area shall be checked with an appropriate refrigerant
detector prior to and during work, to ensure the technician
is aware of potentially toxic or flammable atmospheres.
Ensure that the leak detection equipment being used is
suitable for use with all applicable refrigerants.
If any hot work is to be conducted on the refrigerating
equipment or any associated parts, appropriate fire
extinguishing equipment shall be available to hand. Have a dry
powder or CO fire extinguisher adjacent to the charging area.
2
No person carrying out work in relation to a refrigerating
system which involves exposing any pipe work shall use any
sources of ignition in such a manner that it may lead to the
risk of fire or explosion. All possible ignition sources,
including cigarette smoking, should be kept sufficiently far
away from the site of installation, repairing, removing and
disposal, during which refrigerant can possibly be released
to the surrounding space. Prior to work taking place, the area
around the equipment is to be surveyed to make sure that
there are no flammable hazards or ignition risks. "No
Smoking" signs shall be displayed.
Any deviation or non-observation of these maintenance criteria
will render the guarantee conditions for the HVAC unit null and
void, and the manufacturer will no longer be held responsible.

5.2 - Tightening torques

Every electrical connection use a spring terminal block meaning
that there is no tightening torque specification, excepted those
given below.
Be sure to use ferrules at the end of every clable to avoid any
short circuits.
Screw Type
Protective earth
DIN rails (x4) and PE cables (x2)
screw and grounding
Transformer
Primary and secondary connections
230/24Vac
Sheet metal parts, deflector assembly
Self tapping screw
on front panel & electrical components
Plastic screw
Nut M5 left thread Fan propellers assembly on fan motor
Screw M5x30
Nut M6 BPHE (single-fan units)
BPHE (dual-fan units)
Nut M8
Nut M8 Compressor fixing to base pan
Nut M5 Compressor terminal plug
Obus schrader valve
Cap schrader valve
Water pump inlet and outlet pipe
Nuts water piping
Value
Utilisation
(N.m)
2,7
0,5
3,0
Plastic grid
fan motor
& Receiver fixing
10,5
1,5
Piping 0,35
Piping
connections
5
5
5
45
45
2
40
63