Carrier QHC Series Service Manual page 6

atmosphere.
8. Checks to the refrigeration equipment
Where electrical
changed, they shall be fit for the purpose and to
the correct specification. At all times the
manufacturer's maintenance
guidelines shall be followed. If in doubt consult
the manufacturer's technical department for
assistance. The following checks shall be
applied to installations
refrigerants:

the charge size is in accordance with the

room size within
containing parts are installed;

the ventilation machinery and outlets are

operating adequately and are not obstructed;

if an indirect refrigerating circuit is being

used, the secondary circuit shall be checked
for the presence of refrigerant; marking to the
equipment continues to be visible and legible.

markings and signs that are illegible shall be

corrected;

refrigeration pipe
installed in a position where they are unlikely to
be exposed to any substance which may
corrode refrigerant containing components,
unless the components are constructed of
materials which are inherently resistant to being
corroded or are suitably protected against being
so corroded.
9. Checks to electrical devices
Repair and maintenance
components shall include initial safety checks
and component inspection procedures. If a fault
exists that could compromise safety, then no
electrical supply shall be connected to the
circuit until it is satisfactorily dealt with. If the
fault cannot be corrected immediately but it is
necessary to continue operation, an adequate
temporary solution shall be used. This shall be
reported to the owner of the equipment so all
parties are advised. Initial safety checks shall
include:

that capacitors are discharged: this shall be

done in a safe manner to avoid possibility of
components are
and service
using flammable
which the refrigerant
or components
to electrical
sparking;

that there no live electrical components and
being wiring are exposed while charging, recovering
or purging the system;

that there is continuity of earth bonding.

10. Repairs to sealed components
10.1 During repairs to sealed components, all
electrical supplies shall be disconnected from
the equipment being worked upon prior to any
removal of sealed covers, etc. If it is absolutely
necessary to have an electrical supply to
equipment during servicing, then a permanently
operating form of leak detection shall be
located at the most critical point to warn of a
potentially hazardous situation.
10.2 Particular attention shall be paid to the
following to ensure that by working on electrical
components, the casing is not altered in such a
way that the level of protection is affected. This
shall include damage to cables, excessive
number of connections, terminals not made to
original
are incorrect fitting of glands, etc.

Ensure that apparatus is mounted securely.


Ensure that seals or sealing materials have

not degraded such that they no longer serve
the purpose of preventing the ingress of
flammable atmospheres. Replacement
shall be in accordance with the manufacturer's
specifications.
NOTE: The use of silicon sealant may inhibit
the effectiveness of some types of leak
detection
components do not have to be isolated prior to
working on them.
11. Repair to intrinsically safe components
Do not apply any permanent inductive or
capacitance loads to the circuit without
ensuring
permissible voltage and current permitted for
the equipment
components are the only types that can be
worked on while live in the presence of a
flammable atmosphere. The test apparatus
shall be at the correct rating.
4
specification, damage
equipment. Intrinsically
that this will not
in use. Intrinsically
to seals,
parts
safe
exceed the
safe