Air Handlers Envirofresh Series Guide

INSTALLATION, OPERATION &
MAINTENANCE INSTRUCTIONS FOR:-
SERIES ENVIROFRESH
AIR HANDLING UNITS
CONTRACT No :
PROJECT REF :
AIR HANDLERS LIMITED.
Alfred Proctor House, Bute Street
Weaste, Salford, M50 1DU
TEL :- 0161 745 8888 FAX :- 0161 925 9900
mailto:[email protected]

HEALTH and SAFETY
Working Conditions and Pre-Installation Check
This section deals with the hazards that could be encountered when any work is carried out on
the equipment for which this manual is written.
Therefore the following points should be observed to avoid any injuries or health hazards.
The unit shall be checked to ensure that:
It is suitable for the electrical supply available.
It is suitable for the atmosphere or the environment in which it is to be used.
It is suitable for the working media, temperature and pressure for which it is to be
used.
If the unit is situated in a confined space, suitable ventilation MUST be available to
ensure that any media used (such as ammonia, R22 or R407C) is not injurious to
health.
It is manually isolated from the mains supply before any work is carried out. DO
NOT enter the unit while the fans are running.
Electrical equipment is earthed to comply with I.E.E. regulations and local by-laws.
When starting the electric motor(s) the procedure as laid down in this manual is fully
carried out.
The procedure for removing and replacing timing/wedge belts and filter media (bags
or panels) are fully carried out as laid down in this manual or the suppliers‟ literature.
CAUTIONARY NOTES
No part of the unit shall be dismantled until a careful study has been made of this manual.
This manual deals in detail with erection, commissioning and servicing and shall be strictly
adhered to.
Wherever any maintenance or work is done within the unit, the interior shall be left clean and
all access panels shall be correctly fastened.
Bearing Damage –Cautionary Note
During the interval between delivery and commissioning the drive belts should be slackened
and the fan and motor shafts rotated one quarter of a revolution at intervals of once a week.
Water Treatment (Mandatory)
Check for any treatment that is required to the water supply for prevention of corrosion and
scaling of equipment. Information regarding the necessary action to be taken can be obtained
from the relevant Water Supply Authority, particulars of which can be found in the Waters
Engineers Handbook yearly edition.

DELIVERY
Upon receipt of equipment a visual inspection should be made and any damage noted on the
delivery form. Particulars of any damage or short delivery should be endorsed by the driver
delivering the equipment. No responsibility can be held for damage sustained during the
unloading from the delivery vehicle or on the site thereafter.
All claims for damage or short delivery should be advised to AIR HANDLERS NORTHERN
LTD. in writing within five (5) days of receipt.
OFF LOADING and HANDLING
Each assembly is only to be lifted at the four (4) points when provided on the channel base.
For smaller units nylon straps of the correct capacity should be used. Spreaders must be used
to prevent any damage when lifting using slings or lifting points.
ERECTION of UNIT
Before mounting unit in position it is advisable that consideration is given to the access
requirements of the unit, particularly with reference to the following:
That provision is made in the plant room or wherever the unit is to be installed for access to
remove the following components: Fans
Electric Heater Batteries
Filters (bags or panels)
Coils and Pipework
Access space is also essential for service and maintenance purposes, and for the removal of
the motor(s).
INSTALLATION
All units must be installed in accordance with good engineering standards, upright and levels
on a prepared base. Fixing down of air handling units is at the discretion of the installer and
dependant of the site conditions.
Flexible connections are NOT recommended for connecting ductwork to the unit, as the fan
outlet is fitted with a flexible connector, and is isolated from the unit via anti-vibration
mounts.
Provision must be made for a cleanable drain trap which should terminate at an open drain or
tundish which will ensure any blockage can be seen and remedied.
Units that are delivered in sections should be carefully checked with the general arrangement
drawings to ensure erection in the correct sequence and handing. The sections would be
bolted together using the nuts, bolts and sealant provided.
ELECTRICAL INSTALLATON
Site wiring must not penetrate or restrict opening or removal of access panels.
COMMISSIONING and TESTING
All units should be commissioned before initial operation by the contractors appointed
engineer. Pre-start checks are required in accordance with recommendations laid down in
these instructions. After completion of commissioning all bolts should be tightened and drives
checked for alignment and tension.

MAINTENANCE OF EQUIPMENT HELD IN STORAGE
CONDITIONS FOR A PERIOD UP TO 2 YEARS
Unit Interior and Exterior Surfaces
Interior
If ducting is not connected it is essential that all inlets and discharge openings are completely
sealed.
Exterior
The exterior shall be kept free from falling building materials, dampness or extreme cold or
heat. The unit exterior surfaces should be inspected on a monthly basis and any sign of
corrosion or scratches are to be treated immediately.
Static Indentation
Machines fitted with ball bearings may be damaged if left stationary for long periods. The
balls and races may suffer damage by fretting corrosion (false brinelling, stationary vibration
or static vibration marking).
Wedge Belts and Pulleys
Wedge belts should be removed from the pulleys and hung up and not exposed to excessive
heat or cold and kept free from dampness. Belt life is reduced over a long period of non-use
due to the curing and static condition of rubber.
Pulleys already taper-locked to shafts can be lightly covered with rustproof compound. This
must be thoroughly cleaned off before belting up prior to start up.
Filters
All filters, whether in the form of bags or panels, must be suitably wrapped and sealed to
prevent damp and ingress of dust or foreign bodies, and held in a dry store.
Fan Shaft Bearings
Refer to Bearing damage in Cautionary Notes. Bearings fitted with shields should not be
stored for periods exceeding two (2) years since the grease ages. Bearings stored for longer
periods than that specified may be found to have a higher initial starting torque and the
service life of the grease will then be shortened. It is therefore advisable to repack the grease
after twelve months of non use. Fan shafts and impellers should be protected with rustproof
compound to prevent any corrosion taking place.
Electric Motors
Clean out all the dust accumulated inside and outside the motor and make sure that all the
component parts of the motor are in good condition. Cover all the ventilating holes on the
motor frame to prevent dust from entering the motor. Apply a coating of anti-corrosion grease
or other anti-corrosion agent on all the parts that may be subject to rusting. Care must be
taken to see that the storeroom is always dry and well ventilated while the room temperature
is regularly maintained above 0oC. During storage, periodic inspections should be made to
check for moisture, rust or hardening of grease.
The above are intended to preserve the life of all static and moving parts of the equipment
during the period of storage. It is advisable that regular attention of the equipment is
maintained.

FAN SECTION
Pre-Start Checks
After assembly of Air Handling unit the following checks should be made. Refer to Data
Chart on General Arrangement drawing for specific details.
Isolate electric supply to fan-motor before entering the fan section.
Check pulleys/bushes are secure on shafts and that key is fitted.
Check belt tension; see drivebelt section of this manual for directions.
Check that anti-vibration mountings are level and that bolts are tight
Check motor terminal cover is secure and that bolts are tight.
Test Run
Test run the motor and drive to ensure that the fan is rotating in the right direction. The
correct rotation direction is marked on the fan scroll. If the rotation is in reverse, stop the
motor and reverse any two (2) incoming supply lines to the motor or starter (3 phase supply).
Check that the current being drawn by the motor does not exceed the motor full load current
(indicated on the motor name plate). Note! All access panels must be closed during this test,
otherwise false readings will be obtained.
After 30 minutes operation drive belts should be checked for tension and re-tensioned if
required.
Maintenance
At least every 12 months a major inspection of the fan section should be carried out as
follows:
Isolate electric supply to fan-motor.
Remove and examine drivebelts, check for uneven wear in belts which could indicate
misalignment of pulleys or possible wear to fan bearing.
Rotate and rock shafts of fan and motor to detect bearing play.
Clean fan impeller, any build-up of grease and dust will affect the balance of the fan
causing stresses and decreasing the bearing life.
Inspect all internal and external surfaces for signs of deterioration.
After Inspection and replacement carry out pre-start check and test run.
Fan Maintenance
Frequent inspection should be made of the fan.
General inspection of the fan will depend on how essential the service, the application
operating environment and number of hours run, but should not be more than three monthly
intervals.
On fans operating in dusty atmospheres or exposed to weather then the bearing will need to
be flushed out and replenished with grease every six months.
Recommended Lubricants
Standard fan bearings: - Shell Alvania Grease 3 (or equivalent)
Hot Gas fan bearings: - Shell Alvania Grease RA (or equivalent)

ELECTRIC MOTORS
It is advisable to have a monthly inspection of the motor operation.
Regular cleaning of the motor is necessary during its service. Care must be taken to prevent
moisture, dust, etc from entering the motor.
Ensure that adequate grease lubrication is provided for the bearings when the motor is in
operation. Grease lubricant should be in general replaced every 6 months or immediately
under the following conditions.
Lubricant grease hardened or darkened.
Accumulation of water drops, dust or dirt on the grease surface.
Overheating of the bearings.
When replacing the grease, the bearings should be cleaned and rinsed thoroughly with
gasoline or kerosene after the old grease has been cleaned out. The bearing housing should
then be filled with new grease to 2/3 of its volume. This is very important as impaired
lubrication will result from insufficient or excessive grease.
Built-in lubricating cups and grease relief holes are provided inside both end brackets Ball-
bearing motors are shipped with sufficient grease for a long operating period, if relubrication
is needed, using a low pressure hand-operated grease gun, pump in clean recommended
grease until the new grease appears at the relief hole.
DRIVE BELTS
Belts should be examined each month for tension, alignment and any signs of wear. If one
belt in a matched set is found to be damaged the whole set is to be changed.
Extreme care must be taken when tensioning belts, excessive tension will cause overloading
of bearings and cause damage to bearings, shafts & belts.
Insufficient tension will cause belts slip leading to excessive noise and belt wear.
PIVOT BASE ARRANGEMENT
SLIDE BASE ARRANGEMENT Undo locking nut to release adjustment screw.
Rotate adjustment screw in required direction
to tension/slacken belts. (For tensioning of
belts see directions).
After adjustment re-tighten locking nut.
Adjust angle of pivot base along arms to
tension/slacken belts (For tensioning of
belts see directions).
Ensure pivot base is square with fan and
motor/fan shafts are parallel.
After adjustment re-tighten locking nuts on
both arms.
Adjustment
screw
Locking nut
Slidebase
Pivot base
Adjustment /
locking nuts
Pivot arms

BELT TENSIONING INSTRUCTIONS
Tensioning Forces
Belt Section
Force required to deflect belt 16mm per metre of span
Small Pulley Diameter
Kilogram Force
SPZ
56-95 mm
1.3-2.0 kg
100-140 mm
2.0-2.5 kg
SPA
80-132 mm
2.5-3.6 kg
140-200 mm
3.6-4.6 kg
SPB
112-224 mm
4.6-6.6 kg
236-315 mm
6.6-8.7 kg
SPC
224-355 mm
8.7-11.7 kg
375-560 mm
11.7-15.3 kg
Belt Tensioning Procedure Using A Belt Tension Indicator
Span
Force
Deflection 16mm
per metre of span.
Calculate the deflection distance in mm on a basis of 16mm per metre of
centre distance.
Set the lower marker ring at the deflection distance required in mm on the
lower scale.
Set the upper marker ring against the bottom edge of the tube.
Place the belt tension indicator on top of the belt at the centre of the span, and
apply a force at the right angles to the belt deflecting it to the point where the
lower marker ring is level with the top of the adjacent belt.
Read off the force value indicated by the top edge of the marker ring.
Compare this force to the kgf value in the table above.
If a Belt Tension Indicator is not available, a spring balance and rule will
suffice.
Important
AFTER THE DRIVE HAS BEEN RUNNING FOR APPROXIMATELY 30 MINUTES,
THE TENSION SHOULD BE CHECKED AND RE-ADJUSTED TO THE HIGHER
VALUE, IF NECESSARY.

ELECTRIC AIR HEATER BATTERIES
These should be wired up in accordance with I.E.E. Regulations and local by laws. It is
essential that the heater contactor is interlocked with the fan starter to prevent the heater being
energised when the fans are not running. Additionally it is recommended that a fan run on
facility is included within the controls to dissipate heat form the battery at the end of
operation. All heater batteries incorporate a safety cut-out which must be wired into the
controls system. Ensure the size of cable and contactors are suitable for load being carried. It
is not recommended for P.V.C. cable to be run into the terminal box. The cable should be
insulated with high temperature sleeving.
HEATING and COOLING COILS
General
Coils are normally designed as either cartridge arrangement where they are fitted inside the
casework of the air handling unit, or bolted directly between two sections of the AHU. All
LPHW and chilled water coils are fitted with an air vent and drain plug on the header
connections.
Drain Connections
All cooling coils include a condensate drain tray fitted with a drain connection to be
connected to an appropriate trapping system. Care must be taken to ensure that the correct
type of drain trap is used depending on positive / negative air pressure within the coil section.
Drain lines from the trap must be pitched downwards, a slope of 1 : 25 is recommended.
Installation & Maintenance of Coils
During installation care must be taken to prevent damage being caused to fins, tubes, headers
& return bends of the coil. Damage to fins can be corrected by use of a fin comb (available
from Air Handlers) all coils should be installed level and upright, unless otherwise specified.
Care must be taken to ensure the following conditions are satisfied:-
Water flow & return connections are correctly connected.
All connecting Pipework is independently supported with adequate mountings.
Any pipe movement caused by expansion or contraction must be absorbed by flexible
joints.
Coils located at high points of the system should be regularly vented, other wise coils
may become air locked causing a reduction in duty.
When connecting screwed fittings, it is necessary to restrain the back nut to avoid
damage to the coil.
Coils should be inspected every three (3) months to check for build up of foreign matter
between the fins, and that coil and connections are free from leaks. Should any foreign matter
be found cleaning should be carried out with a high pressure air line directed at the air off
face of the coil. Alternatively the coil can be washed down with a mild solution of detergent
and water, after which the coil should be thoroughly rinsed with clean water.
Eliminators should be cleaned down using a soft brush and hot water, any sediment cleared
out of drain tray and drain pipe, and if necessary repair any areas of corrosion.
Condensate Removal From Steam Coils
When air, water, or another product is heated, the temperature or heat transfer rate can
be regulated by a modulating steam pressure control valve. Since pressure and
temperature do not vary at the same rate as load, the steam trap capacity, which is
determined by the pressure differential between the trap inlet and outlet, may be
adequate at full load, but not at some lesser load.

Analysis shows that steam pressure must be reduced dramatically to achieve a slight
lowering of temperature. In most applications this can result is sub-atmospheric
pressure in the coil, while as much as 75% of full condensate load has to be handled
by the steam trap. This is especially important for coils exposed to outside air, since
sub-atmospheric conditions can occur in the coil at outside temperatures below 32oF
(0oC) and the coil will freeze if the condensate is not removed. There are detailed
methods for determining condensate load under various operating conditions.
However, on most cases, this load does not need to be calculated if the coils are piped
as shown in the figure below and this procedure is followed.
breaker
Vacuum
Regulating
valve
Condensate
Trap
Supply
To atmoshperic drain or receiver,
COIL
Trap
Air purge
min.
300
Do not lift except by pump.
The steam trap should be 1 to 3ft (0.3 to 0.9m) below the bottom of the steam coil to
provide a hydraulic head of approximately 0.5 to 1.5 psig (3.5 to 10.3kpa above atm.).
Location of the trap at less than 12in (300mm) minimum usually results in improper
drainage and operating difficulties.
Vacuum breakers must be installed between the coil and the trap inlet to
ensure that the hydraulic head drain the coil when it is at atmospheric or sub-
atmospheric pressure. The vacuum breaker should respond to a differential
pressure of no greater than 3in. of water (750pa). For atmospheric returns, the
vacuum breaker should be opened to the atmosphere, and the return system
must be designed to ensure no pressurization of the return line. In vacuum
return systems, the vacuum breaker should be piped to the return line.
Discharge from the trap must flow by gravity, without any lifts in the piping,
to the return system, which must be vented properly to the atmosphere to
eliminate any back pressure that could prevent the trap from draining the coil.
Where the return main is overhead, the trap discharge should flow by gravity
to a vented receiver, from which it is then pumped to the overhead return.
Traps must be designed to operate at maximum pressure at the control valve
inlet and sized to handle the full condensate load at a pressure differential
equal to the hydraulic head between the trap and coil. Since the actual
condensate load can vary from the theoretical design load because of the
safety factors used in coil selection and the fact that condensate does not
always form at a uniform steady rate, steam traps should be sized according to
the following:-

0-15pisg (0-100kpa above atm.) at the control valve inlet: size the trap
for twice the full condensate load (coil condensing rate at maximum
design conditions) at 0.5psi (3kpa) pressure differential.
16-30psig (110 to 200kpa above atm.) at the control valve inlet: size
the trap for twice the full condensate load at 2psi (14kpa) pressure.
31psig (210kpa above atm.) and over at the control valve inlet: size the
trap to handle triple the full condensate load at a pressure differential
equal to half the control valve inlet pressure.
The steam supply must be drained of entrained condensate prior to
entering the coil, preferably, just before the regulating valve.
RECUPERATORS
Maintenance
Recuperator units have no moving parts, hence mechanical maintenance is unnecessary.
When dealing with dusty and polluted air, filters should be regularly checked and replaced
when necessary. It is possible to clean the unit with compressed air (in case of dust deposit) or
by spraying it with a detergent solution in case of any greasy deposits.
In order to remove greasy deposits, a water-detergent solution such as DECADE, ND-150
CHEM ZYME, PRIMASEPT, POLY-DET, oakite 86m or similar should be used, following
the manufacturers instructions.
Strongly alkaline or any products that may be aggressive to aluminium should be avoided.
DAMPERS
Installation
When connecting ductwork to dampers take care to ensure that damper casing is not twisted
by ductwork and that fixings do not penetrate cog housing of the damper which will affect the
damper mechanism. Ductwork must be independently supported and should not be left to
hang from the damper. Sealing should be in the form of prestik or neoprene strip.
Ensure actuator rotation is correct in relation to blade location to prevent breaking linkages.
Maintenance
At six (6) month intervals disconnect actuator and check for freedom of movement.
AIR FILTERS
COSHH Regulations
The components of filters are inherently safe, but changing air filters could expose operators
to a „Nuisance Dust‟ hazard. We would therefore recommend that filter changing be carried
out by maintenance personnel wearing simple dust masks, eye protection, overalls or
protective clothing & gloves. Dirty filters should be sealed into plastic bags for disposal.
Disposable Filters
These are supplied in the forms of panel & bag filters and are fitted into steel channel runners.
Filters are simply withdrawn through the access door by sliding the filter along the channel
runner.Alternatively,bagfiltersmayberetainedbythumbscrewsandclampbars.Ensureall
screwsareloosenedbeforeattemptingtoremoveeachbagfilter. Filters should generally be
replaced when the pressure drop increases to 0.5”wg
(125pa) above the initial level.
Washable Panel Filters
Generally as per disposable filters except when pressure drop indicates dirty filter conditions,
filters should be fully immersed in warm water to which a mild detergent has been added.
Agitate the filter until clean, rinse and allow to dry before replacing.

HEPA Filters (High Efficiency Particle Arrestors)
This type of filter is generally fitted in front withdrawal frame. Filters will be held into the
frame by retaining bars which can be removed to allow access to replace filters.
Carbon Filters
Carbon filters normally have an active life of about twelve (12) months, or more. It is
advisable to remove a sample from the pack to return to manufacturer to determine the
remaining working life, preferably after the first six (6) months & subsequent six (6) monthly
intervals.
NOTE! WHEN REPLACING ALL FILTERS ENSURE FILTER IS FACING CORRECT
DIRECTION AS INDICATED BY AN AIRFLOW ARROW.
ROUTINE MAINTENANCE SCHEDULE
Monthly
3 Monthly
6 Monthly
Annually
Fan Shaft Bearings
Motors
Belts & Pulleys
Elec. Heater Battery
Coils
Eliminators
Dampers
Panel & Bag Filters
HEPA Filters
Carbon Filters
External Surfaces
MAINTENANCE OF UNITS CONTAINING F GAS REFRIGERANTS.
It is a legal requirement that all units containing F Gas refrigerants such as R407c, R410a are
serviced on a regular basis and that leak tests are carried out. This should generally be carried
out at least every six months and a service inspection sheet issued to the customer upon
completion. Log books should be kept on site by the end user to prove that these works have
been carried out. The responsibility of compliance is shared by the end user and the appointed
maintenance engineers.
Failure to comply with the F Gas regulations will result in invalidation of the warranty on the
refrigeration system within the unit.
INVALIDATION OF GUARANTEE
The following misuses or maltreatment of AIR HANDLERS LIMITED equipment will
render all guarantees, as set out on the Conditions of Sale, void.
Failure to install, set up or put to work any part of the equipment as specified in AIR
HANDLERS LIMITED Installation, Operation and Maintenance Instructions.
Attempting to operate the motors and other electrical equipment with an electrical
supply other than that designated on the motor nameplate, or failing to connect and
protect such equipment in accordance with I.E.E. Regulations and local by-laws.
Failure to notify AIR HANDLERS LIMITED of equipment damaged on receipt in
writing within five (5) days.
Failure to run equipment within the design specifications as notified at the time of
order.

Modifications to designed arrangement or performances without the prior written
approval of AIR HANDLERS LIMITED.
Damage caused to equipment on site through lack of adequate protection from the
elements or misuse by other trades.
Failure to observe all normally accepted engineering practices during installation,
commissioning and subsequent operation of equipment.

Refrigeration Maintenance
SAFETY WARNING: Ensure that all power to the unit is switched off before carrying
out any servicing or maintenance task.
Only trained and qualified service personnel should repair or service air
conditioning equipment containing a refrigeration system.
Follow all safety codes. Wear safety glasses and work gloves.
Extinguish any cigarette or naked flame.
If on inspection of the refrigeration pressures a refrigerant leak is suspected,
open all access panels to ensure the gas has dissipated to atmosphere.
ACCESS The access panel to the refrigeration service valves and switches is
identified by a red flammability label. Access to the compressor section is
identified on the unit drawing.
SERVICE CHECKS At every service visit the following checks should be carried out: -
4 MONTHLY
REFRIGERATION Check the suction and discharge pressures using a service gauge
CIRCUITS manifold and compare them with the commissioning sheet. If there is any
significant variation, then the fault should be found and corrected. Refer to
the troubleshooting chart. If on inspection of the refrigeration pressures a
refrigerant leak is suspected, open all access panels to ensure the gas has
dissipated to atmosphere.
Visually examine pipework and components for damage, wear and tear and
oil patches, the latter being indicative of a system leak.
Check that the high and low pressure switches are cutting out the
compressors at the correct settings.
High pressure switch cut-out 320psi
Low pressure switch cut-out 30psi
Low pressure switch cut-in 50psi
The gauges can then be removed from the system. Do not forget to replace
the security caps on the Schrader valves.
ELECTRICAL Check all electrical connections for signs of overheating or arcing.
Check all cables for signs of chafing or physical damage.
SERVICE CHECKS As four monthly plus the following: -
YEARLY
Check all electrical connections for tightness.
Check all refrigeration connections with a foam or detergent leak detector.

Troubleshooting –General
FAULT POSSIBLE CAUSE REMEDY / ACTION
Unit not operating.
No Supply or Extract fans
running.
No air volume.
Low air volume, fans
running, air flow fail on.
No heating or cooling
Low heating output or air
volume.
No power to unit.
Time clock output.
Fire link open.
Defective damper end
switch.
No power to fans
Fan drive or motor failure
Filters blocked
Incoming phases crossed.
Temperature controller
Fan drive or motor failure
Refrigeration fault.
Compressor fault
indication.
Dirty filters.
Defective recovery damper
actuator (SHC).
Filters freezing.
Frost coil not operational.
Outdoor coil freezing.
Re-heat coil not
operational.
Check isolator, mains supply.
Check settings.
Inspect fireman‟s panel.
Check actuator operation and end switch
making when open.
Check control switch, fuses, MCB`s and
control circuit wiring.
Inspect drive belts. Check motor winding
resistance. Inspect fan pressure switch
and tubing and replace.
Remove packaging or replace.
Check fan rotation. If incorrect change
mains incoming unit phases over. Not
individual fans.
Adjust set point control. Check
operation.
Inspect drive belts. Check motor winding
resistance. Inspect fan pressure switch
and tubing and replace.
Refer to refrigeration section.
Refer to refrigeration section.
Replace filters.
Check bypass damper closed on heating
demand. Replace if faulty.
.
Check frost coil.
Check set points on thyrister controller
and check operation.
Check defrost stat operation.
Investigate operation of main step
controller.

ENVIROFRESH SHC/TA
Troubleshooting –General
FAULT POSSIBLE CAUSE REMEDY / ACTION
Low cooling output.
Frost coil fault light
indication.
Re-heat fault light (SHC
only) indication.
Supply airflow failed
indication.
Extract airflow failed
indication.
Filter dirty indication
Noise from fan section.
Dirty filters.
Compressor fault.
Cooling hold off stat.
Indoor coil freezing.
Fan run on timer faulty.
Unit power isolated or
power cut, bypassing auto
controls.
Power isolated by fire
alarm interlock
Fan run on timer faulty.
Unit power isolated or
power cut, bypassing auto
controls.
Power isolated by fire
alarm interlock
Fan motor or drive failure
Fan motor or drive failure.
Dirty filters.
Transit straps not removed
Replace filters.
Refer to compressor section.
Check operation and settings.
Check operation and settings of the
indoor frost protection stat.
Check fan runs on to dissipate heat prior
to unit shut down. Replace if faulty and
reset heater cut out switch
Ensure unit shut down via automatic
controls. Reset heater cut out switch.
Switch off unit via automatic controls
prior to tests if possible. Reset heater cut
out switch.
Check fan runs on to dissipate heat prior
to unit shut down. Replace if faulty and
reset heater cut out switch
Ensure unit shut down via automatic
controls. Reset heater cut out switch.
Switch off unit via automatic controls
prior to tests if possible. Reset heater cut
out switch.
Inspect drive belts. Check motor winding
resistance and contactors. Inspect fan
pressure switch and tubing and replace.
Inspect drive belts. Check motor winding
resistance and contactors. Inspect fan
pressure switch and tubing and replace.
Change filters.
Remove.

ENVIROFRESH SHC/TA
Troubleshooting –Refrigeration
FAULT POSSIBLE CAUSE REMEDY / ACTION
Compressor not operating
Noisy compressor.
Compressor fault
indication.
HP fault indication.
LP fault indication
No power to compressor
Seized compressor,
Defective compressor
motor.
Incorrect rotation.
Expansion valve
malfunction.
Lack of oil.
Overload trip.
HP switch faulty.
Reduced airflow.
System overcharged.
Apparent with high room
or external temps.
Coil clogged.
Liquid line valve not
energized.
LP switch faulty
Reduced airflow
Icing coil.
Lack of refrigerant.
Clogged filter drier.
Check fuses, MCBs, contactors, and
control circuit wiring. Step energised on
controller.
Check air flow failure switches.
Check delay timer operation, check
controller timer operation. Change
compressor.
Check winding resistance-replace
compressor.
Change phase rotation. Check phase
rotational devise.
Ensure feeler bulb is tight on suction and
superheat is correct at 50C.
Repair leaks if any, add oil if required.
Reset and investigate reason.
Check cut out pressure and replace if
necessary.
Reset switch, check volumes, change
filters.
Reset switch, remove excess refrigerant.
Clean coil.
Defective solenoid. Replace. Check
control feed.
Check cut out pressure and replace if
necessary.
Reset switch, check volumes, change
filters.
Check defrost and frost stat, gas charge
and expansion valve.
Check for leaks- repair and recharge
system
Replace.

ENVIROFRESH SHC/TA
Troubleshooting –Refrigeration
FAULT POSSIBLE CAUSE REMEDY / ACTION
Suction pressure too low.
Insufficient cooling
(High suction, low head)
Insufficient cooling
(Low suction, low head)
Insufficient cooling(High
suction, low superheat)
Insufficient cooling
(Low suction, high head)
Insufficient heating (low
suction, low head)
Insufficient heating (High
suction, low superheat)
Insufficient heating (low
suction high head)
System not changing over
to heating
Reduced airflow.
Clogged filter drier.
Obstruction in expansion
valve.
4 port valve not fully
engaged or internal leak.
Icing coil.
Low on refrigerant.
Indoor check valve leaking.
Outdoor check valve not
fully open.
Icing coil.
Low on refrigerant.
4 port valve not fully
engaged or internal leak.
Outdoor check valve
leaking.
System overcharged.
Outdoor check valve stuck
closed.
4 port valve not operating
or stuck.
Check volumes, change filters.
Replace.
Inspect, clean or replace.
Try to free by valve by operating or
replace.
Check air volume and indoor frost stat.
Check for leaks- repair and recharge
system
Replace.
Replace.
Check air volume and de-frost stat.
Check for leaks- repair and recharge
system
Try to free by valve by operating or
replace.
Replace.
Reduce charge.
Replace.
Defective solenoid. Replace. Check
control feed. Try to free by valve by
operating or replace.

AHU - HEALTH AND SAFETY REQUIREMENTS
Manufacturers Responsibility
Fan section access - All access doors allowing entry to the fan section are to be fitted
with one lockable door handle to prevent unauthorised access. Additionally these
doors are to display a suitable warning label.
Electric Heater access - Non lockable lift off electric heater access panels are to
display a suitable electric warning label.
Specification - Additional safety guards and features (such as driveguard, fan inlet
guards, bulkhead lights etc.) will be fitted when requested in the specification and
included within our quotation.
Humidifiers - Copper steam pipework between humidifiers and distribution pipes
where installed by ourselves will be lagged to prevent exposure of hot surfaces. When
humidifier steam pipework installation is not carried out by ourselves it is the
installers‟ responsibility to ensure correct lagging.
Installers Responsibility
Installation - Unless otherwise specified by ourselves this product is supplied with
the intention to be incorporated into other equipment or fitted into a ducted ventilation
system or similar suitable application. Some installations may require additional
safety parts to ensure safe operation. For example, fan fitted at the end of a ducted
system with the inlet or outlet open exposing the impeller/motor to unguarded access.
In this event the installer must fit a safety guard complying with current regulations.
Isolators - Isolators are to be fitted locally to all fan motors and other electrical
components of the AHU to allow safe working on the equipment.
Humidifiers - See “Humidifiers” section above.
End Users responsibility
All AHU‟s are despatched with keys tied to door handles, it is the responsibility of the
end user after hand-over to ensure that all keys are kept safe by a responsible person
and only issued to authorised personnel.