Daikin Rebel Applied DPSA - Checks to electrical devices; Repairs to sealed components; Repair to intrinsically safe components; Cabling

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www.DaikinApplied.com 91 IM 1287-6 • REBEL APPLIED ROOFTOP
The following checks shall be applied to installations
using FLAMMABLE REFRIGERANTS:
• The actual REFRIGERANT CHARGE is in accordance
with the room size within which the refrigerant 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 that are illegible shal be corrected.
• Refrigerating pipe or components are 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.
Checks to electrical devices
Repair and maintenance to electrical 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 sparking;
• that no live electrical components and wiring are exposed
while charging, recovering or purging the system;
• that there is continuity of earth bonding.
Repairs to sealed components
• 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.
• 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
a󰀨ected. This shall include damage to cables, excessive
number of connections, terminals not made to original
specication, damage to seals, incorrect tting of glands,
etc.
• Ensure that the apparatus is mounted securely.
• Ensure that seals or sealing materials have not degraded
to the point that they no longer serve the purpose of
preventing the ingress of ammable atmospheres.
Replacement parts shall be in accordance with the
manufacturer’s specications.
Repair to intrinsically safe components
• Do not apply any permanent inductive or capacitance
loads to the circuit without ensuring that this will not
exceed the permissible voltage and current permitted for
the equipment in use.
• Intrinsically safe components are the only types that can
be worked on while live in the presence of a ammable
atmosphere. The test apparatus shall be at the correct
rating.
• Replace components only with parts specied by the
manufacturer. Other parts may result in the ignition of
refrigerant in the atmosphere from a leak.
NOTE: The use of silicon sealant can inhibit the e󰀨ectiveness
of some types of leak detection equipment.
Intrinsically safe components do not have to be
isolated prior to working on them.
Cabling
• Check that cabling will not be subject to wear, corrosion,
excessive pressure, vibration, sharp edges or any other
adverse environmental e󰀨ects. The check shall also take
into account the e󰀨ects of aging or continual vibration
from sources such as compressors or fans.
Detection of ammable refrigerants
• Under no circumstances shall potential sources of ignition
be used in the searching for or detection of refrigerant
leaks. A halide torch (or any other detector using a naked
ame) shall not be used.
• The following leak detection methods are deemed
acceptable for all refrigerant systems.
• Electronic leak detectors may be used to detect
refrigerant leaks but, in the case of FLAMMABLE
REFRIGERANTS, the sensitivity may not be adequate,
or may need re-calibration. (Detection equipment shall
be calibrated in a refrigerant-free area.) Ensure that
the detector is not a potential source of ignition and
is suitable for the refrigerant used. Leak detection
equipment shall be set at a percentage of the LFL of
the refrigerant and shall be calibrated to the refrigerant
employed, and the appropriate percentage of gas (25 %
maximum) is conrmed.
• Leak detection uids are also suitable for use with most
refrigerants but the use of detergents containing chlorine
shall be avoided as the chlorine may react with the
refrigerant and corrode the copper pipe-work.
NOTE: Examples of leak detection uids are
— bubble method
— uorescent method agents.
• If a leak is suspected, all naked ames shall be removed/
extinguished.
• If a leakage of refrigerant is found which requires brazing,
all of the refrigerant shall be recovered from the system,
or isolated (by means of shut o󰀨 valves) in a part of the
system remote from the leak. Removal of refrigerant shall