Thermoscreens PHV2000NT Installation, Operation & Maintenance Instructions Manual

T9901018-1 Page 1 of 26

PHV2000NT CHILLED WATER HEAT PUMP,

SENSIBLE/DRY COOLING UNIT

INSTALLATION, OPERATION & MAINTENANCE INSTRUCTIONS

For use with PUHZ-HW140VHA2 or YHA2 Outdoor Units

PLEASE READ THESE INSTRUCTIONS CAREFULLY BEFORE ATTEMPTI NG INSTALLATION

Thermoscreens Ltd

St. Mary’s Road Nuneaton

Warwickshire England

CV11 5AU

Email: [e-mail]

Tel: [phone]
Fax: [phone]

www.thermoscreens.com

English

T9901018-1 Page 2 of 26

Thermoscreens / Mitsubishi Electric

PHV2000NT Chilled Water Heat Pump,

Dry Cooling Unit - Split System

The PHV2000NT Chilled Water Heat Pump System consists of :-

 a Thermoscreens 'PHV2000NT Dry Cooling Unit' with Mitsubishi Electric PAC-IF010B-

E Interface PCB and PAR-W21MAA Controller and Siemens RDG400 Manual Room
Control for manual control by the end user *

 a Mitsubishi Electric PUHZ-HW140VHA2/YHA2 Air to Water Outdoor Unit *

* - supplied by Mitsubishi Electric

 Water Pipework Installation and Water Pump(s) ‡
 Electrical installation ‡
 a 2-pole On/Off Switch for the end user ‡
 a 2-pole Isolator for the S1, S2, S3 link ‡

‡

- installation items supplied and fitted by installer

Thermoscreens PHV2000NT

Dry Cooling Unit

Mitsubishi Electric

PUHZ-HW140

Outdoor Unit

Permanent 1-phase mains electrical supply

Siemens RDG400

Manual Room Control

On/Off – Input
Cooling Temp Set Point – Input
Air Temp Sensor – Input
(alternative to return air temp sensor in unit)

S1, S2, S3 link

Permanent electrical supply

(from local switched isolator)

Pump

Flow and Return water pipework

Remote Signals

On/Off - Input
Mitsubishi Error - Output
Room over-temp alarm - Output

Chilled water pipework
Electrical cables

Control cables

Supplied and fitted inside plastic end
cap. Not used for control by the end
user, only needed so the outdoor
unit will run.

2-pole On/Off Switch for End User
(easily accessible next to unit)
[connect fire alarm circuit here]

Mitsubishi Electric

PAR-W21MAA

S1, S2

Isolator

T9901018-1 Page 3 of 26

DESIGN INFORMATION

The Thermoscreens dry cooling unit is designed to provide up to 12kW * of dry/sensible
cooling (SHR/SHF = 1) (e.g. zero latent cooling with no condensate coming from the unit)
to areas where cooling is required but with no increase in moisture content of the air, i.e. IT
Server Rooms, laboratory areas, etc. It will do this if the room environmental conditions are
no higher than 24°C dry bulb with a relative humidity no greater than 40% and the chilled
water flow temperature entering the unit is no lower than 10°C **. The 10°C chilled water
flow temperature is set at commissioning and controlled by the Mitsubishi Electric PUHZ­HW140 Outdoor Unit. Under design conditions the return water temperature from the dry
cooling unit is 13°C with a flow water temperature of 10°C.

* - output may be reduced if antifreeze additives are used.
** - validated by tests carried out at independent test house BSRIA, UK.

Chilled water pipework and water pump(s) must be supplied and installed to supply the
chilled water from the PUHZ-HW140 Outdoor Unit to the Thermoscreens dry cooling unit.
Hydraulic details for this installation are as follows:

Table 1

Water Volume

Flow Rate for

12kW maximum

output

Hydraulic

Resistance of

water coil in

Thermoscreens

Dry Cooling Unit at

3.2 m

3

/h

(kPa)

Hydraulic

Resistance of heat

exchanger in

Mitsubishi PUHZ

Outdoor Unit at

3.2 m3/h
(kPa)

Water Volume of

water coil in

Thermoscreens

Dry Cooling Unit

(litre)

Water Volume of

heat exchanger in

Mitsubishi PUHZ

Outdoor Unit

(litre)

m3/h l/min

3.2 53 36 15 5.1 2.5

A separate, self contained ‘closed/unvented’ water system must be used for the flow and
return water pipework between the Thermoscreens dry cooling unit and the Mitsubishi
Electric outdoor unit. This should incorporate water pump(s), expansion vessel, pressure
relief valve, filling loop, pressure gauge, automatic air vents, water dirt trap device, flow
setter valve (recommended), drain valve(s), isolating valves and union fittings for the
removal of components. The water system must be suitable for chilled water and installed
and commissioned by a qualified technician in accordance with CIBSE Commissioning
Code W, CIBSE KS9, BSRIA AG 2/89.3 and BSRIA AG 1.2001.1. For the Mitsubishi
Electric system to operate correctly the minimum water volume of the water system must
be 80 litres, so a buffer vessel may be necessary. A water dirt trap device should be
incorporated into the chilled water system to help protect the system from any
contamination and provide an ongoing indication of the system water condition. Please
note that the Fernox Boiler Buddy water dirt trap device has a hydraulic pressure drop of
12kPa (clean) at a water flow rate of 3.2m3/h**. If pressure drop in the system becomes an
issue it may be necessary to use a commercial type water strainer with a lower hydraulic
pressure drop. It is recommended that a flow setter valve is fitted in the water pipework
system to verify the water flow rate. We recommend the AV23 SETTER Bypass SD 20-70
l/min DN32 (Code No.223.2561.00) by Taconova www.taconova.com or equivalent.

For a self contained, close coupled 35mm pipework installation the following suggested
water pumps are given as a guide only :-

Wilo TOP-S 30/10 (230V/1ph/50Hz) or Grundfos UPS32-120F (230V/1ph/50Hz)

Pump selection must of course be checked by a Building Services Engineer for
each installation !

T9901018-1 Page 4 of 26

Because of the relatively high hydraulic pressure drops it may be cost effective to
incorporate two water pumps operating in series. Pump(s) need to be 230V/1ph/50Hz with
a total maximum current = 2A for all pumps combined. If the pump(s) total current is higher
than this an interface relay/contactor will need to be used.

If so required, the cooling duty can be reduced from 12kW and a smaller water pump
used. Dry cooling will still be achieved providing the room environmental conditions are no
higher than 24°C dry bulb with a relative humidity no greater than 40% and the chilled
water flow temperature entering the unit is no lower than 10°C. The following table gives
details for this:

Table 2

Cooling Duty

(kW)

Water Volume

Flow Rate

Water Return

Temperature

(

°C)

Hydraulic Resistance

of water coil in

Thermoscreens Dry

Cooling Unit

(kPa)

Hydraulic Resistance

of heat exchanger in

Mitsubishi PUHZ

Outdoor Unit

(kPa)

m3/h l/min

11.5 2.6 44 13.8 24 10

11.0 2.0 33 14.8 14 6

10.5 1.6 26 15.7 9 4

Calculated for Water Flow Temperature = 10°C

In case of emergency, condensate could form on the cooling coil if there was a failure in
the air conditioning on site or environmental conditions in the server room went above
24°C/40%Rh due to some other circumstance, e.g. doors left open, extreme weather
conditions. To allow for this the Thermoscreens dry cooling unit is supplied with an integral
condensate drain tray and outlet pipe to drain condensate away from the unit. A gravity
condensate drain system extending to a suitable drain outside of the room must be
supplied and fitted by the installer in case this emergency situation were to occur. This
should be connected to the 15mm copper drain pipe that protrudes from the right-hand
rear of the cooling unit behind the plastic end cap. Condensate pumps are not
recommended but if a gravity drain system is impossible and a condensate pump is the
only alternative it must not be fitted at the dry cooling unit because of reliability issues with
these devices. If the condensate needs to be pumped to a higher level with a condensate
pump this should be done in a separate room away from the server room. If there was a
spillage of condensate at the pump, therefore, it will not occur in the server room. Suitable
condensate pumps are Peristaltic or Rotary Diaphragm type with a suction head. The
condensate pump needs to have the facility so it only operates if water is detected in the
drain tray. It should also have a pump overrun to empty the drain tray as much as
possible. We recommend the Blue Diamond rotary diaphragm type with cooling signal
sensor (drainStik) manufactured by Charles Austen Pumps Ltd. (www.miniblue.co.uk).

The condensate drain tray inside of the Thermoscreens dry cooling unit has a metal fixing
bracket located at the right hand end so a condensate sensor can be fixed in the tray in
the appropriate position by the installer. There is a rubber grommet with 9.5mm hole fitted
in the fixing bracket which will accept a 10mm diameter condensate sensor. Different size
grommets can be fitted by the installer to suit other condensate sensors or if the grommet
is removed a larger condensate sensor can be located in the 13mm diameter hole in the
fixing bracket and held with silicon sealant. See also the manufacturer’s instructions that
come with the condensate pump for further information.

Valuable or delicate equipment should not be placed beneath the dry cooling unit or
directly in the path of the cool air discharge from the unit.

T9901018-1 Page 5 of 26

The Thermoscreens dry cooling unit operates from its own separate 1 phase electrical
supply (1L+N+E) with a local switched isolator, see Page 12, and the fan within the unit
runs continuously when this electrical supply is connected. If the local switched isolator is
not easily accessible by the end user there should be a 2-pole On/Off switch fitted in an
easily accessible position next to the dry cooling unit. The Mitsubishi Electric interface pcb
fitted inside the dry cooling unit, however, is powered via the S1, S2, S3 wiring from the
outdoor unit and a 2-pole S1, S2 isolator is required for this electrical/communications link.

Room temperature control of the Thermoscreens dry cooling unit is done using a Siemens
RDG400 Manual Room Control that is supplied with the unit. This room control is used to
select the target temperature (set point) of the room air temperature and it then switches
the Mitsubishi Electric cooling system On and Off to achieve this temperature. The room
air temperature is measured using either a return air temperature sensor in the air intake
of the dry cooling unit or via an integral air temperature sensor within the RDG400 manual
room control. This is selectable at the time of commissioning. A volt free remote On/Off
control switch or BMS Dig/Output signal can be connected to the Thermoscreens dry
cooling unit to turn the cooling system On and Off as an alternative to manually switching it
On and Off at the RDG400 manual room control via the target temperature.

A separate thermostat with its air sensor positioned in the air intake is incorporated within
the Thermoscreens dry cooling unit. This is to provide warning of elevated room air
temperatures which could indicate a fault in the air conditioning system or some other
problem. This thermostat can be set during commissioning to between 15°C and 35°C and
terminals are provided within the unit for external monitoring of the contacts opening or
closing on rising temperature. Contacts are rated 16A(4A) at 230v AC.

The Thermoscreens dry cooling unit includes the facility to provide a global error signal
should an error occur in the Mitsubishi Electric heat pump system.

A Mitsubishi Electric PAR-W21MAA Remote Controller is supplied and pre-fitted inside the
left hand end cap of the Thermoscreens dry cooling unit. It is needed for the Mitsubishi
Electric heat pump system to operate and is also useful to diagnose error messages. It is
not used for control of the system by the end user, this is done via the Siemens RDG400
manual room control, see above.

The Thermoscreens dry cooling unit is designed only for use with a Mitsubishi Electric air
to water heat pump system for use on R410A. The complete Thermoscreens/Mitsubishi
Electric air to water heat pump system, including fridge pipework, water pipework system,
wiring, controls, etc. must be installed only by an approved Mitsubishi Electric refrigeration
contractor in accordance with the relevant installation instructions.

Persons using the dry cooling system must be given adequate instruction and supervision
concerning the use of the appliance by a person responsible for their safety. The cooling
system is not intended for use by persons (including children) with reduced physical,
sensory or mental capabilities.

These instructions must be read in conjunction with the separate Mitsubishi Electric
instructions that come with the PUHZ-HW140 Outdoor Unit. All instructions should be kept
by the building facilities manager for future reference.

T9901018-1 Page 6 of 26

UNPACKING THE DRY COOLING UNIT

The following items are supplied and packaged within the dry cooling unit box :-

There will also be a PUHZ-HW140VHA2 or YHA2 Air to Water Outdoor Unit supplied by
Mitsubishi Electric.

The complete Thermoscreens/Mitsubishi Electric dry cooling system, to provide dry cooling to
a server room or other space, including chilled water pipework system and wiring is to be
installed only by an approved Mitsubishi Electric contractor.

For your records

Date of Purchase……………………………..
Supplier/Installer………………………..…….
Serial Number…………………………………

For warranty purposes proof of purchase is necessary so please keep a copy of your invoice.

IMPORTANT
This Dry Cooling Unit is intended only for use with a Mitsubishi Electric
PUHZ-HW140VHA2 or YHA2 Air to Water Outdoor Unit.

These instructions must be read in conjunction with the separate instructions that
come with the Mitsubishi Electric PUHZ-HW140VHA2 or YHA2 Air to Water Outdoor
Unit.

(All documentation supplied with the unit should be stored and kept for future reference.)

If anything is missing or
damaged please contact
your supplier immediately.

PHV2000NT Dry Cooling Unit

End caps are supplied loose to
be fitted during installation

Mitsubishi Electric PAR-W21MAA
fitted inside LH end cap

Siemens RDG400

M

anua

l Room Control

Wall Brackets and Fixing Bolts

for if Dry Cooling Unit is to be fixed to a wall

T9901018-1 Page 7 of 26

150mm
minimum clearance

COOL AIR

White unit shown for picture clarity only

INSTALLING THE DRY COOLING UNIT

The dry cooling unit has been designed to be mounted on a wall or suspended from
above using M10 drop rods. It must not be installed on the outside of the building,
or built into a cabinet or recessed in anyway.

Location

The dry cooling unit must be mounted so the unit is
horizontal and level and the discharge grille faces
downwards. The discharge grille must be at least

2.4m above ground level and located so the
downwards flowing cool air will distribute throughout
the room or across equipment to be cooled. It
should not, however, be positioned directly above
valuable or delicate equipment in case of water
leaks or an emergency condensate situation, e.g.
doors left open, extreme weather conditions.
Beware of obstructions in the room that may
interfere with air distribution. Leave a gap of 150mm
minimum above the unit to allow for installing the water pipework.

Wall Fixing

There are three wall brackets supplied and these need to
be bolted to the rear face of the cooling unit as shown in
the adjacent picture using the M10 bolts supplied. A
suitable wall fixing system (not supplied) needs to be
used to fix the brackets to the wall, taking into account the
type of wall and the weight of the unit - 76kg.*

Step 1. Refer to Figure 1, Page 8 for mounting details
and drill the fixing points in the wall.
Step 2. Screw in the top wall bolts leaving a small gap
between the bolt head and the wall. Lower the cooling
unit onto the bolts via the key-hole slots in the top of the
wall brackets and then screw in the bottom wall bolts.
Step 3. Ensure all fixing bolts are tightened and the dry
cooling unit is safely secured to the wall.

Ceiling Suspension

There are six M10 threaded inserts provided in the top
face of the cooling unit (see Figure 1, Page 8 for
positions) so it can be suspended on M10 threaded
hanging rods with lock nuts (not provided). All six
suspension points must be used. Ensure each of the
hanging rods is secured onto a suitable structure that can
support the weight of the unit - 76kg.* Screw the M10
hanging rods into the threaded inserts by a minimum of
20mm and fit locking nuts to prevent the rod rotating and
coming away from the casing. Do not screw the hanging
rods too far in or they could interfere with internal
components.

* It is the sole responsibility of the installer to ensure that

the building fixing locations and suspension system used
are suitable for the dry cooling unit being installed.

White unit shown for picture clarity only

T9901018-1 Page 8 of 26

295

912

1824

798

1596

2296

168

36

255

377

Water Return Connection

60

Electrical Supply and

Control Wiring Inlets

for pipes

c. 150 min.

6 x M10 threaded holes for M10 drop rods

IMPORTANT - Use all 6 drop rod holes

3 Holes x 20mm

Water Connections, Rp1

56

70

(1in. BSP Internal.)

Emergency Condensate Connection

at rear of plastic end cap, 15mm copper

798

215

912

AIR

AIR

Wall Mounting Brackets

FLOW RETURN

Water Flow Connection

FIGURE 1 – DIMENSIONS OF THERMOSCREENS DRY COOLING UNIT