Servicing and Repair Information
Fig. 15 Fan Belt Tensioning
POUNDS OF FORCE
BELT SPAN
DEFLECTION
(Shaft Center Distance)
Ideal belt tension is the lowest value under which belt slip will not
occur at peak load conditions.
Belt drives should not squeal under peak load conditions. If
neces
sary, stop the drive, then start it again. If a squeal is heard,
the belts should be tightened to the point where they do not
squeal under peak load. Newly installed belts require about 24
hours to become fully seated in the groove.
Always check the drive alignment after adjusting belt tension.
16 Servicing and Repair Information
16.1 Confined Space Work
Work in confined spaces must be avoided.
16.2 Controlled Work Procedure
All work must be undertaken under a controlled procedure to
minimize the risk of a flammable gas or vapor being present while
the work is being performed.
16.3 Safety Checks
Prior to beginning work on systems containing flammable
refrigerants, safety checks are necessary to ensure that the risk
of ignition is minimized. The following precautions must be taken
prior to conducting work on the refrigerating system.
16.3.1 Inform Everyone in the General Work Area
All maintenance staff and others working in the local area must be
instru
cted on the nature of work being carried out.
16.3.2 Check for the Presence of Refrigerant
The area must be checked with an appropriate refrigerant
detecto
r 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
R-454B refrigerant;
i.e.
, non-sparking, adequately sealed, or
intrinsically safe.
16.3.3 Fire Extinguisher
If any hot work is to be conducted on the refrigerating equipment
or any a
ssociated parts, appropriate fire-extinguishing
equipment must be available on hand. Have a dry powder or CO
2
fire extinguisher adjacent to the charging area.
16.3.4 Ignition Sources
Ensure the following prior to the 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 must be posted.
All possible ignition sources, including cigarette smoking,
must be kept sufficiently far away from the site of installation,
repair, removal, or disposal during which refrigerant may
possibly be released and exposed to the surrounding area
and the ignition sources.
Ensure that any person carrying out work in relation to a
refrigerating system that involves exposing any pipe work
knows that they must NOT use any sources of ignition in such
a manner that it may lead to the risk of fire or explosion.
16.3.5 Ventilated Area
Ensure that the area is in the open or that it is adequately
ventila
ted before breaking into the system or conducting any hot
work. The ventilation must safely disperse all released
refrigerant, preferably expelling it externally into the
atmosphere. The ventilation must be present during the period
that the work is carried out.
16.3.6 Checks to the Refrigerating Equipment
Where electrical components are being changed, they must be fit
for the
purpose and to the correct specification. At all times the
manufacturer's maintenance and service guidelines must be
followed. If in doubt, consult Bosch service and support for
assistance.
The following checks must be applied to installations using
flamm
able refrigerants:
Ensure the actual refrigerant charge is in accordance with the
room size within which the refrigerant containing parts are
installed.
Ensure that the ventilation machinery and outlets are
operating adequately and are not obstructed.
Check the secondary circuit for the presence of refrigerant, if
an indirect refrigerating circuit is being used.
36 |
EC Series Heat Pumps — 8733841499 (2024/05)
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