LG Therma V ZHBW056A0 User manual

AIR-TO-WATER HEAT PUMP
SERVICE MANUAL
(General)
CAUTION
Before Servicing the unit, read the safety precautions in General SVC manual.
Only for authorized service personnel.
CONFIDENTIAL
Copyright © 2018 LG Electronics Inc. All rights reserved. Only training and service purposes.

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Copyright © 2018 LG Electronics Inc. All rights reserved.
Only training and service purposes.
AWHP Service Manual
TABLE OF CONTENTS
Safety Precaution
Part 1 : General Information
1. Model Information
2. External Appearance
Part 2 : Features & Controls
1. List of Function
2. Feature & Controls
3. Test Run
Part 3 Basic Control
Part 4 :Replacement
1. Replacement procedure for Compressor
2. Replacement Procedure for INV PCB
3. Caution for Assembling Outdoor Panels after Test Run
Part 5 : Trouble Shooting
1. Checking Key Components of Indoor Unit
2. Checking Key Components of Outdoor Unit
3. Self-Diagnosis Feature
4. Trouble Shooting Guide

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Copyright © 2018 LG Electronics Inc. All rights reserved.
Only training and service purposes.
Safety Precautions
To prevent injury to the user or other people and property damage, the following instructions must be followed.
nIncorrect operation due to ignoring instruction will cause harm or damage. The seriousness is classified by the
following indications.
WARNING
CAUTION
This symbol indicates the possibility of death or serious injury.
This symbol indicates the possibility of injury or damage to properties only.
nMeanings of symbols used in this manual are as shown below.
Be sure not to do.
Be sure to follow the instruction.
Dangerous Voltage
Read the precautions in this manual carefully
before operating the unit.
This appliance is filled with flammable
refrigerant (R32)
This symbol indicates that the Operation
Manual should be read carefully.
This symbol indicates that a service
personnel should be handling this equipment
with reference to the Installation Manual.
1.1 Safety Precautions in Repair
WARNING
Be sure to disconnect all remote electric power supplies before servicing. Internal
components and circuit boards are at main potential when the equipment is
connected to the power cables. This voltage is extremely dangerous and may
cause death or severe injury if come in contact with it.
Do not touch the discharging refrigerant gas during the repair work.
The refrigerant gas can cause frostbite.
Release the refrigerant gas completely at a well-ventilated place first.
Otherwise, when the pipe is disconnected, refrigerant gas or refrigerating machine
oil discharges and it can cause injury.
When the refrigerant gas leaks during work, execute ventilation. If the refrigerant
gas touches to a fire, poisonous gas generates. A case of leakage of the
refrigerant and the closed room full with gas is dangerous because a shortage of
oxygen occurs. Be sure to execute ventilation.
When removing the front panel or cabinet, execute short-circuit and discharge
between high voltage capacitor terminals. If discharge is not executed, an electric
shock is caused by high voltage resulted in a death or injury.
Be sure to provide the grounding when repairing the equipment in a humid or
wet place, to avoid electrical shocks.

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Copyright © 2018 LG Electronics Inc. All rights reserved.
Only training and service purposes.
Do not use a defective or underrated circuit breaker. Use the correctly rated
breaker and fuse. Otherwise there is a risk of fire or electric shock.
Install the panel and the cover of control box securely. Otherwise there is risk of
fire or electric shock due to dust, water etc.
Do not touch, operate, or repaire the product with wet hands. Hoding the plug by
hand when taking out. Otherwise there is risk of electric shock or fire.
Use a vacuum pump or Inert (nitrogen) gas when doing leakage test or air purge.
Do not compress air or Oxygen and Do not use Flammable gases. Otherwise, it
may cause fire or explosion.
- There is the risk of death, injury, fire or explosion.
Do not turn on the breaker or power under condition that front panel, cabinet, top
cover, control box cover are removed or opened.
Otherwise, it may cause fire, electric shock, explosion or death.
The appliance shall be stored so as to prevent mechanical damage from occurring
Any person who is involved with working on or breaking into a refrigerant circuit
should hold a current valid certificate from an industry-accredited assessment
authority, which authorises their competence to handle refrigerants safely in
accordance with an industry recognised assessment specification.
Servicing shall only be performed as recommended by the equipment
manufacturer. Maintenance and repair requiring the assistance of other skilled
personnel shall be carried out under the supervision of the person competent in
the use of flammable refrigerants.
Keep any required ventilation openings clear of obstruction
• Refrigerant tubing shall be protected or enclosed to avoid damage.
• The installation of pipe-work shall be kept to a minimum
• When flared joints are reused indoors, the flare part shall be re-fabricated.
• When mechanical connectors are reused indoors, sealing parts shall be renewed.

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Copyright © 2018 LG Electronics Inc. All rights reserved.
Only training and service purposes.
• Do not use means to accelerate the defrosting process or to clean, other than
those recommended by the manufacturer.
• Do not pierce or burn.
• Be aware that refrigerants may not contain an odour.
• Ducts connected to an appliance shall not contain an ignition source.
• Two or more people must lift and transport the product. Avoid personal injury.
• Periodic (more than once/year) cleaning of the dust or salt particles stuck on the
heat exchanger by using water.
• Dismantling the unit, treatment of the refrigerant oil and eventual parts should
be done in accordance with local and national standards.
Checks to the area
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 precautions shall be complied with prior to
conducting work on the system.
Work procedure
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.
General work area
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 around the workspace shall be sectioned off. Ensure that the conditions
within the area have been made safe by control of flammable material.
Checking for presence of refrigerant
The area shall be checked with an appropriate refrigerant detector prior to and
during work, to ensure the technician is aware of potentially flammable
atmospheres. Ensure that the leak detection equipment being used is suitable for
use with flammable refrigerants, i.e. non-sparking, adequately sealed or intrinsically
safe.
Presence of fire extinguisher
If any hot work is to be conducted on the refrigeration equipment or any
associated parts, appropriate fire extinguishing equipment shall be available to
hand. Have a dry powder or CO2 fire extinguisher adjacent to the charging area.
• Pipe-work shall be protected from physical damage and shall not be installed in
an unventilated space, if that space is smaller than
1) The minimum floor area : 49.4 m2
2) The maximum refrigerant charge amount : 2.4 kg

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Copyright © 2018 LG Electronics Inc. All rights reserved.
Only training and service purposes.
No ignition sources
No person carrying out work in relation to a refrigeration system which involves
exposing any pipe work that contains or has contained flammable refrigerant 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 flammable 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.
Ventilated area
Ensure that the area is in the open or that it is adequately ventilated before
breaking into the system or conducting any hot work. A degree of ventilation shall
continue during the period that the work is carried out. The ventilation should
safely disperse any released refrigerant and preferably expel it externally into the
atmosphere.
Checks to the refrigeration equipment
Where electrical components are being changed, they shall be fit for the purpose
and to the correct specification. At all times the manufacturer’s maintenance and
service guidelines shall be followed. If in doubt consult the manufacturer’s
technical department for assistance.
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 and signs
that are illegible shall be corrected
- Refrigeration 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.

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Copyright © 2018 LG Electronics Inc. All rights reserved.
Only training and service purposes.
Initial safety checks shall include
- Capacitors are discharged: this shall be done in a safe manner to avoid
possibility of sparking.
- No live electrical components and wiring are exposed While charging, recovering
or purging the system.
- 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
affected. This shall include damage to cables, excessive number of connections,
terminals not made to original specification, damage to seals, 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 parts shall be in
accordance with the manufacturer’s specifications
NOTE
The use of silicon sealant can inhibit the effectiveness of some types of leak
detection equipment. Intrinsically safe components do not have to be isolated prior
to working on them.
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 flammable atmosphere.
The test apparatus shall be at the correct rating. Replace components only with
parts specified by the manufacturer. Other parts may result in the ignition of
refrigerant in the atmosphere from a leak
Cabling Check
Cabling will not be subject to wear, corrosion, excessive pressure, vibration, sharp
edges or any other adverse environmental effects. The check shall also take into
account the effects of ageing or continual vibration from sources such as
compressors or fans.
Detection of flammable 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 flame) shall not be used.

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Copyright © 2018 LG Electronics Inc. All rights reserved.
Only training and service purposes.
Leak detection methods
The following leak detection methods are deemed acceptable for systems
containing flammable refrigerants. Electronic leak detectors shall be used to detect
flammable refrigerants, but 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 confirmed. Leak detection fluids
are 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. If a leak is suspected, all naked flames 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 off valves) in a part of the system remote from the leak. Oxygen free nitrogen
(OFN) shall then be purged through the system both before and during the brazing
process.
Removal and evacuation
When breaking into the refrigerant circuit to make repairs – or for any other
purpose - conventional procedures shall be used. However, it is important that
best practice is followed since flammability is a consideration. The following
procedure shall be adhered to:
- Remove refrigerant
- Purge the circuit with inert gas
- Evacuate
- Purge again with inert gas
- Open the circuit by cutting or brazing.
The refrigerant charge shall be recovered into the correct recovery cylinders. The
system shall be “flushed” with OFN to render the unit safe. This process may need
to be repeated several times. Compressed air or oxygen shall not be used for this
task. Flushing shall be achieved by breaking the vacuum in the system with OFN
and continuing to fill until the working pressure is achieved, then venting to
atmosphere, and finally pulling down to a vacuum. This process shall be repeated
until no refrigerant is within the system. When the final OFN charge is used, the
system shall be vented down to atmospheric pressure to enable work to take
place. This operation is absolutely vital if brazing operations on the pipe-work are
to take place. Ensure that the outlet for the vacuum pump is not close to any
ignition sources and there is ventilation available.

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Copyright © 2018 LG Electronics Inc. All rights reserved.
Only training and service purposes.
Charging procedures
In addition to conventional charging procedures, the following requirements shall
be followed.
- Ensure that contamination of different refrigerants does not occur when using
charging equipment. Hoses or lines shall be as short as possible to minimise the
amount of refrigerant contained in them.
- Cylinders shall be kept upright.
- Ensure that the refrigeration system is earthed prior to charging the system with
refrigerant.
- Label the system when charging is complete (if not already).
- Extreme care shall be taken not to overfill the refrigeration system. Prior to
recharging the system it shall be pressure tested with OFN. The system shall be
leak tested on completion of charging but prior to commissioning. A follow up leak
test shall be carried out prior to leaving the site.
Decommissioning
Before carrying out this procedure, it is essential that the technician is completely
familiar with the equipment and all its detail. It is recommended good practice that
all refrigerants are recovered safely. Prior to the task being carried out, an oil and
refrigerant sample shall be taken in case analysis is required prior to re-use of
reclaimed refrigerant. It is essential that electrical power is available before the
task is commenced.
a) Become familiar with the equipment and its operation.
b) Isolate system electrically.
c) Before attempting the procedure ensure that: • mechanical handling equipment
is available, if required, for handling refrigerant cylinders; • all personal
protective equipment is available and being used correctly; • the recovery
process is supervised at all times by a competent person; • recovery equipment
and cylinders conform to the appropriate standards.
d) Pump down refrigerant system, if possible.
e) If a vacuum is not possible, make a manifold so that refrigerant can be removed
from various parts of the system.
f) Make sure that cylinder is situated on the scales before recovery takes place.
g) Start the recovery machine and operate in accordance with manufacturer's
instructions.
h) Do not overfill cylinders. (No more than 80 % volume liquid charge).
i) Do not exceed the maximum working pressure of the cylinder, even temporarily.
j) When the cylinders have been filled correctly and the process completed, make
sure that the cylinders and the equipment are removed from site promptly and all
isolation valves on the equipment are closed off.
k) Recovered refrigerant shall not be charged into another refrigeration system
unless it has been cleaned and checked.
Labelling
Equipment shall be labelled stating that it has been de-commissioned and emptied
of refrigerant. The label shall be dated and signed. Ensure that there are labels on
the equipment stating the equipment contains flammable refrigerant.

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Copyright © 2018 LG Electronics Inc. All rights reserved.
Only training and service purposes.
Recovery
When removing refrigerant from a system, either for servicing or decommissioning,
it is recommended good practice that all refrigerants are removed safely.
When transferring refrigerant into cylinders, ensure that only appropriate
refrigerant recovery cylinders are employed. Ensure that the correct number of
cylinders for holding the total system charge are available. All cylinders to be used
are designated for the recovered refrigerant and labelled for that refrigerant (i.e.
special cylinders for the recovery of refrigerant). Cylinders shall be complete with
pressure relief valve and associated shut-off valves in good working order. Empty
recovery cylinders are evacuated and, if possible, cooled before recovery occurs.
The recovery equipment shall be in good working order with a set of instructions
concerning the equipment that is at hand and shall be suitable for the recovery of
flammable refrigerants. In addition, a set of calibrated weighing scales shall be
available and in good working order. Hoses shall be complete with leak-free
disconnect couplings and in good condition. Before using the recovery machine,
check that it is in satisfactory working order, has been properly maintained and
that any associated electrical components are sealed to prevent ignition in the
event of a refrigerant release. Consult manufacturer if in doubt. The recovered
refrigerant shall be returned to the refrigerant supplier in the correct recovery
cylinder, and the relevant Waste Transfer Note arranged. Do not mix refrigerants in
recovery units and especially not in cylinders. If compressors or compressor oils
are to be removed, ensure that they have been evacuated to an acceptable level
to make certain that flammable refrigerant does not remain within the lubricant.
The evacuation process shall be carried out prior to returning the compressor to
the suppliers. Only electric heating to the compressor body shall be employed to
accelerate this process. When oil is drained from a system, it shall be carried out
safely.
The appliance shall be stored in a well-ventilated area where the room size
corresponds to the room area as specified for operation
The appliance shall be stored in a room without continuously operating open
flames (for example an operating gas appliance) and ignition sources (for example
an operating electric heater).
The appliance shall be stored so as to prevent mechanical damage from occurring
Compliance with national gas regulations shall be observed
The installation of pipe-work shall be kept to a minimum
A brazed, welded, or mechanical connection shall be made before opening the
valves to permit refrigerant to flow between the refrigerating system parts. A
vacuum valve shall be provided to evacuate the interconnecting pipe and/or any
uncharged refrigerating system part.