Lennox MMA036S4 - Ventilated Workspace

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1.4. Ventilated Workspace
Ensure the work area is adequately ventilated before
breaking into the system or conducting any hot work.
Maintain ventilation until service is complete. The
ventilation should safely disperse any released refrigerant
and expel it externally into the atmosphere.
1.5. Check Refrigeration Equipment
If changing electrical components, verify the components
are a correct t and appropriately serves the purpose.
Verify the following points when executing installations that
require ammable refrigerants.
• The charge size 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 must be checked for the presence
of refrigerant marking to the equipment continues to
be visible and legible.
• Correct any illegible markings and signs
• Refrigeration pipe or components are installed in a
position where they are unlikely to be exposed to any
substance that may corrode refrigerant containing
components, unless the components are constructed
of materials that are inherently resistant to corrosion
1.6. Check Electrical Devices
Repair and maintenance to electrical components must
include initial safety checks and component inspection
procedures. If a fault exists that could compromise safety,
do not connect any electrical supply to the circuit until
the issue is resolved. If the fault cannot be corrected
immediately but it is necessary to continue operation, an
adequate temporary solution can be used. Report the
temporary solution to the owner of the equipment so all
parties are advised. Initial safety checks include:
• Capacitors are discharged; use caution to avoid the
possibility of sparking
• No live electrical components and wiring are exposed
while charging, recovering, or purging the system
• Continuity of earth bonding
1.7. Repair Seal Components
During repairs to sealed components, all electrical supplies
must be disconnected from the equipment being serviced
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 must be located at the most critical point to warn
of a potentially hazardous situation.
Pay close attention to the following to ensure safety when
servicing electrical components:
• Casing is not altered in such a way that negatively
a󰀨ects the level of protection (damage to cables,
excessive number of connections, terminals
not made to original specication, damage to
seals,incorrect tting of glands, etc.)
• Ensure the apparatus is mounted securely
• Ensure that seals or sealing materials have not
degraded or no longer can prevent the ingress of
ammable atmospheres. Replacement parts must be
in accordance with the manufacturer’s specications.
NOTE: The use of silicon sealant may inhibit the
eectiveness of some types of leak detection
equipment. Intrinsically safe components do not
have to be isolated prior to servicing them.
1.8. Repair to Intrinsically Safe
Components
When repairing intrinsically safe components:
• Do not apply any permanent inductive or capacitance
loads to the circuit without ensuring it will not exceed
the permissible voltage and current permitted for the
equipment in use.
• Intrinsically safe components are the only types of
components that can be serviced while live in the
presence of a ammable atmosphere.
• The test apparatus must 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.
1.9. Check Cabling
When conducting the safety check, consider the e󰀨ects
of aging or continual vibration from sources such as
compressors or fans. Verify cabling is not positioned in an
environment that will make it vulnerable to wear, corrosion,
excessive pressure, vibration, sharp edges or any other
adverse environmental e󰀨ects.