Daikin EWAD-D-H 200 Installation, Operation And Maintenance Manual Download

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Evaporator and recovery exchangers anti-freeze protection

All evaporators are supplied with a thermostatically controlled
anti-freeze electrical resistance, which provides adequate anti-
freeze protection at temperatures as low as

–25°C. However,

unless the heat exchangers are completely empty and cleaned
with anti-freeze solution, additional methods should also be
used against freezing.
Two or more of below protection methods should be
considered when designing the system as a whole:



Continuous water flow circulation inside piping and
exchangers



Addition of an appropriate amount of glycol inside the
water circuit



Additional heat insulation and heating of exposed piping



Emptying and cleaning of the heat exchanger during the
winter season

It  is  the  responsibility  of  the  installer  and/or  of  local
maintenance  personnel  to  ensure  that  described  anti-freeze
methods  are  used.  Make  sure  that  appropriate  anti-freeze
protection  is  maintained  at  all  times.  Failing  to  follow  the
instructions  above  could  result  in  unit  damage.  Damage
caused by freezing is not covered by the warranty.

Installing the flow switch

To  ensure  sufficient  water  flow  through  the  evaporator,  it  is
essential  that  a  flow  switch  be  installed  on  the  water  circuit.
The  flow  switch  can  be  installed  either  on  the  inlet  or  outlet
water piping. The purpose of the flow switch is to stop the unit
in  the  event  of  interrupted  water  flow,  thus  protecting  the
evaporator from freezing.
The  manufacturer  offers,  as  optional,  a  flow  switch  that  has
been selected for this purpose.
This paddle-type flow switch is suitable for heavy-duty outdoor
applications (IP67) and pipe diameters in the range of 1” to 6”.
The flow switch is provided with a clean contact which must be
electrically  connected  to  terminals  shown  in  the  wiring
diagram.
Flow  switch  has  to  be  tune  to  intervene  when  the  evaporator
water flow is lower than 50% of nomila flow rate.

Heat recovery

Units may be optionally equipped with heat recovery system.
This  system  in  made  by  a  water  cooled  heat  exchanger
located  on  the  compressors  discharge  pipe  and  a  dedicated
managment of condensing pressure.
To  gurantee  compressor  operation  within  its  envelope,  units
with  heat  recovery  cannot  operate  with  water  temperature  of
the heat recovery water lower than 28°C.
It  is  a  responsability  of  plant  designer  and  chiller  installer  to
grantee  the  respect  of  this  value  (e.g.  using  recirculating
bypass valve)

Electrical Installation

General specifications

All electrical connections to the  unit must be carried out
in compliance with laws and regulations in force.
All  installation,  management  and  maintenance  activities
must be carried out by qualified personnel.
Refer to the specific wiring diagram for the unit you have
bougth. Should the  wiring  diagram  not  be  on the  unit  or
should  it  have  been  lost,  please  contact  your
manufacturer representative, who will send you a copy.
In  case  of  discrepance  between  wiring  diagram  and
electrical  panel/cables  please  contact  the  manufacturer
representative.

Only use copper conductors. Failure to use copper conductors
could  result  in  overheating  or  corrosion  at  connection  points
and could damage the unit.
To  avoid  interference,  all  control  wires  must  be  connected
separately  from  the  power  cables.  Use  different  electrical
passage ducts for this purpose.
Before  servicing  the  unit  in  any  way,  open  the  general
disconnecting switch on the unit

’s main power supply.

When the unit is off but the disconnecting switch is in the
closed position, unused circuits are live, as well.

Never open the terminal board box of the compressors before
having o

pened the unit’s general disconnecting switch.

Contemporaneity  of  single-phase  and  three-phase  loads  and
unbalance  between  phases  could  cause  leakages  towards
ground up to 150mA, during the  normal operation of the units
of the series.
If the unit includes devices that cause superior harmonics (like
VFD  and  phase  cut),  the  leakage  towards  ground  could
increases to very higher values (about 2 Ampere).
The  protections  for  the  power  supply  system  have  to  be
designed according to the above mentioned values.

Operation

Operator’s responsibilities

It  is  essential  that  the  operator  is  appropriately  trained  and
becomes familiar with the system before operating the  unit. In
addition  to  reading  this  manual,  the  operator  must  study  the
microprocessor  operating  manual  and  the  wiring  diagram  in
order  to  understand  start-up  sequence,  operation,  shutdown
sequence and operation of all the safety devices.
During the unit

’s initial start-up phase, a technician authorized

by the manufacturer is available to answer any questions and
to give instructions as to the correct operating procedures.
The operator must keep a record of operating data for every
installed unit. Another record should also be kept of all the
periodical maintenance and servicing activities.
If the operator notes abnormal or unusual operating conditions,
he is advised to consult the technical service authorized by the
manufacturer.

Routine maintenance

Minimum maintenance activities are listed in

Table

Service and limited warramty

All units are factory-tested and guaranteed for 12 months as of
the first start-up or 18 months as of delivery.
These  units  have  been  developed  and  constructed  according
to  high  quality  standards  ensuring  years  of  failure-free
operation.  It  is  important,  however,  to  ensure  proper  and
periodical  maintenance  in  accordance  with  all  the  procedures
listed  in  this  manual  and  with  good  practice  of  machines
maintenance.
We  strongly  advise  stipulating  a  maintenance  contract  with  a
service  authorized  by  the  manufacturer  in  order  to  ensure
efficient and problem-free service, thanks to the expertise and
experience of our personnel.
It  must  also  be  taken  into  consideration  that  the  unit  requires
maintenance also during the warranty period.

It  must  be  borne  in  mind  that  operating  the  unit  in  an
inappropriate  manner,  beyond  its  operating  limits  or  not
performing  proper  maintenance  according  to  this  manual  can
void the warranty.
Observe  the  following  points  in  particular,  in  order  to  conform
to warranty limits:
1.

The unit cannot function beyond the specified limits

The electrical power supply must be within the voltage
limits and without voltage harmonics or sudden changes.

The three-phase power supply must not have un
unbalance between phases exceeding 3%. The unit must
stay turned off until the electrical problem has been
solved.

No safety device, either mechanical, electrical or
electronic must be disabled or overridden.

The water used for filling the water circuit must be clean
and suitably treated. A mechanical filter must be installed
at the point closest to the evaporator inlet.

Unless there is a specific agreement at the time of
ordering, the evaporator water flow rate must never be
above 120% and below 80% of the nominal flow rate.