Robur GAHP Line AR Series User manual

GAHP Line AR Series
Air-Water reversible absorption heat pumps
for heating and cooling medium-large areas
Natural gas/LPG fired
Installation, use and
maintenance manual

EDITION: 2014-08
CODE: D-LBR364
This manual was written and printed by Robur Corporation; part or total reproduction of
this manual is prohibited.
The original is filed at Robur Corporation.
Any use of this manual other than for personal consultation must be previously authorized
by Robur Corporation.
The rights of those who have legitimately filed the registered trademarks contained within
this publication are not affected.
With the aim of continuously improving the quality of its products, Robur Corporation
reserves the right to modify the data and contents of this manual without prior notice.

Foreword
Ed. 2014-08 I
FOREWORD
This manual is designed to be an installation and user’s guide for the Robur GAHP-AR,
Gas Absorption Heat Pumps series.
This manual especially applies to the plumbing and electrical installers for the hook-up of
the GAHP-AR and the initial configuration, and also for the end user regarding its use.
This manual also has a section regarding the operations that must be done before the first
start-up and the primary maintenance operations.
Summary
This manual is composed of 6 sections and an appendix:
SECTION 1 pertains to the end user, the plumbing installer and the electrical installer; it
provides general warnings, technical data and the construction characteristics of the
GAHP-AR.
SECTION 2 is for the end user; it provides all the information necessary for the correct
use of the GAHP-AR in relation to the end user’s needs.
SECTION 3 is for the plumbing installer; it provides the necessary indications to the
plumber in order to correctly install the GAHP-AR.
SECTION 4 is for the electrical installer; it provides the necessary information to the
electrician in order to make the GAHP-AR electrical connections.
SECTION 5 provides the instructions to regulate the flow of gas and to perform the gas
conversion. It also gives indications regarding maintenance.
SECTION 6 pertains to the end user, the plumbing installer and the electrical installer. It
contains information regarding the available GAHP-AR spare parts.
The table of the machine codes is reported in the APPENDIX.
To quickly access these sections, make reference to the relative graphical icon (see Table
2, page II) seen in the right hand margin of odd numbered pages.
References
If the GAHP-AR is to be connected to a Direct Digital Controller (DDC), refer to the
following documentation supplied with it:
- DDC manual for the electrical installer (electrician) – book 1.
- DDC manual for the end user – book 2.

GAHP-AR – Installation, start-up, use and maintenance manual
II Edition: 2014-08
Icon meaning definition
The icons present in the margins of the manual have the following meanings:
Danger
Warning
Note
Operational procedure start
Reference to another part of the manual or to a different
manual/book
Table 1 – Description icons
OVERVIEW and technical SPECIFICATIONS
End user
Plumbing installer
Electrical installer
First start-up and maintenance
Optionals and Spare Parts
Table 2 – Section icons

Index
Ed. 2014-08 1
INDEX OF CONTENTS
SECTION 1 OVERVIEW AND TECHNICAL SPECIFICATIONS .....................................3
1.1 WARNINGS........................................................................................................................................ 3
1.2 OPERATION OF THE GAHP-AR ...................................................................................................... 6
1.3 TECHNICAL DATA ............................................................................................................................ 9
1.4 GAHP-AR DIMENSIONS ................................................................................................................. 14
SECTION 2 END USER ..................................................................................................15
2.1 ACTIVATION (AND DEACTIVATION) OF THE APPLIANCE ......................................................... 15
2.2 ON-BOARD ELECTRONICS ........................................................................................................... 17
2.3 OPERATING SETTINGS ................................................................................................................. 21
2.4 RESET OPERATIONS AND MANUAL DEFROSTING COMMAND ............................................... 21
2.5 PROLONGED PERIODS OF DISUSE............................................................................................. 24
SECTION 3 PLUMBING INSTALLER.............................................................................27
3.1 GENERAL INSTALLATION PRINCIPLES....................................................................................... 27
3.2 POSITIONING OF THE APPLIANCE .............................................................................................. 28
3.3 HYDRAULIC CONNECTIONS......................................................................................................... 32
3.4 GAS SUPPLY SYSTEM................................................................................................................... 37
3.5 FILLING OF HYDRAULIC CIRCUIT (to be carried out by installation technician) .......................... 39
3.6 GAS PRESSURE ADJUSTEMENT ................................................................................................. 41
3.7 CONNECTION OF COMBUSTION PRODUCT EXHAUST PIPE ................................................... 43
3.8 PROGRAMMING OF HYDRAULIC PARAMETERS ....................................................................... 44
SECTION 4 ELECTRICAL INSTALLER .........................................................................49
4.1 S61 AND UNIT ELECTRICAL DIAGRAM KEY ............................................................................... 50
4.2 OPERATION WITH ON/OFF COMMAND SWITCH........................................................................ 52
4.3 CONTROL OF PLANT PUMP.......................................................................................................... 54
4.4 PUMP AND ELECTRICAL WIRING DIAGRAMS ............................................................................ 55
4.5 USE OF THE DIRECT DIGITAL CONTROLLER (DDC) ................................................................. 58
SECTION 5 FIRST START-UP AND MAINTENANCE ...................................................67
5.1 PROCEDURE FOR FIRST START-UP ........................................................................................... 68
5.2 MAINTENANCE ............................................................................................................................... 73
5.3 CHANGE OF GAS TYPE................................................................................................................. 76
SECTION 6 OPTIONALS AND SPARE PARTS .............................................................79
APPENDIX........................................................................................................................89
IGNITION CONTROL BOX ..................................................................................................................... 89
WARNINGS AND ERRORS.................................................................................................................... 90
TABLE OF OPERATING CODES (firmware release 3.027)................................................................... 91

GAHP-AR – Installation, start-up, use and maintenance manual
2Edition: 2014-08

Overview and technical specifications section
Ed. 2014-08 3
SECTION 1 OVERVIEW AND TECHNICAL SPECIFICATIONS
In this section you will find the general instructions to follow for the installation of the
GAHP-AR, outlines on the running of the unit, constructive characteristics and technical
data.
1.1 WARNINGS
This manual is an integral and essential part of the product and must be given to the end
user along with the GAHP-AR.
This appliance must be used exclusively for its intended purpose. All chilling and heating
applications must be in accordance with the operating specifications of the unit. Any other
use is considered improper and, therefore, dangerous.
Steps must be taken to avoid improper use and potential dangers.
The operational conditions and authorized areas of use are reported in paragraph 1.3
TECHNICAL DATA, page 9.
The manufacturer will not accept contractual or non-contractual liability for
damages caused to people, animals, or things due to incorrect installation and
improper use of the GAHP-AR and also by not observing the indications and
instructions provided by the manufacturer.
Codes and standards
The installation of the appliance must conform with local building codes or, in the absence
of local codes, with the National Fuel Gas Code, ANSI Z223.1, the Natural Gas
Installation Code, CAN/CGA-B149.1, or the Propane Installation Code, CAN/CGA-B149.2,
as applicable.
The appliance electrical connections and grounding must be in accordance with any local
codes, or in the absence of local codes, with the latest edition of the National Electrical
Codes, ANSI/NFPA No. 70 (CSA Standard C22.1 when installed in Canada) and with any
local codes. To ensure the electrical safety of this appliance, it must be correctly
connected to an efficient grounding system. The manufacturer is not responsible for any
damages caused by the failure of the grounding system.
At the installation spot
After delivery of the GAHP-AR and at the location where it is to be installed, check the
GAHP-AR to make sure there are no signs of damage to the packaging or to the external

GAHP-AR – Installation, start-up, use and maintenance manual
4Edition: 2014-08
paneling, an indication of possible damage during transportation. After removal of the
packaging material, ensure that the GAHP-AR is whole and complete.
Do not leave the packaging material within the reach of children (plastic bags,
Styrofoam spacers and insulators, nails, etc.), because they can be sources of
danger.
The GAHP-AR has a sealed circuit that can be classified as a pressurized vessel;
this means that its internal pressure is greater than the atmospheric pressure. The
fluids inside the sealed circuit are dangerous to one’s health if ingested, inhaled or
if they come in contact with the skin.
Do not perform any interventions on either the sealed circuit or the valves on the
GAHP-AR. If operation on the sealed circuit is necessary, call a qualified technician
or engineer.
Only qualified technicians, strictly complying with the manufacturer’s instructions and the
local standards, should install this product. The manufacturer will not accept responsibility
for personal injuries or property damage resulting from improper installation.
A “Qualified Technician” is defined as someone having specific technical
competence in the air conditioning/heating and gas appliances, according to
international and national standards.
In particular, current laws must be respected with regard to:
- Natural gas equipment
- Electrically powered equipment
- Any other standard that regulates the installation of air conditioning devices with
gaseous fuel.
Before starting the appliance
Before installation, carefully clean the internal tubing and water components, both
on the fuel side and the water system side; this is to remove any residue which
could compromise the functioning of the GAHP-AR.
The company qualified to install the GAHP-AR must verify that:
•the electric and gas supply ratings are the same as those on the data plate
•the gas tubing system and the water distribution system are sealed
•the GAHP-AR is supplied with the type of gas for which it is preset
•the gas supply pressure is within the rating limits indicated by the manufacturer
•the gas and electric supply systems are suitable for the capacity needed by the
GAHP-AR and that they are equipped with all safety and checking devices required
by current regulations; the electrical safety of the GAHP-AR chiller is achieved only

Overview and technical specifications section
Ed. 2014-08 5
when it is properly connected to an efficient grounding system, done according to
electrical safety standards in force.
Do not operate the GAHP-AR if electrical or safety components have been
excluded, by-passed or do not function correctly.
If the above mentioned conditions have been satisfied, the installation procedure (done by
the qualified company) and the successive start-up (done by a Robur Corporation
authorized Technical Service Centre, "TAC") may begin.
The initial start-up of the GAHP-AR must only be done by a Robur Corporation
authorized Technical Service Centre (TAC) following the indications provided by
the manufacturer. The warranty of the GAHP-AR is effective only if validated by a
Robur Corporation "TAC".
In case of fault during installation and ignition with the smell of natural gas
If you smell gas:
•Do not operate electrical devices near the GAHP-AR, such as telephones, multi-
meters or other devices that can create sparks.
•Close the gas supply valve.
•Shut off electrical power to the GAHP-AR.
•Call a Qualified Service Engineer using a telephone that is not near the GAHP-AR.
In case of fault during installation and ignition without the smell of natural gas
In case of fault or poor functioning of the GAHP-AR without the escape of gas,
immediately shut it down using the appropriate control switch (see “ACTIVATION (AND
DEACTIVATION) OF THE APPLIANCE”, page 15); if the shutdown cycle begins, wait for
it to complete, which takes about 10 minutes; remove electrical power by shutting off the
main power switch and close the gas valve. If the shutdown cycle does not start due to an
occurring problem, directly shut off the electrical power and gas supplies.
Do not attempt any type of intervention or repair.
Perform these operations even if the cooling unit has not been used for a long period of
time, see the “PROLONGED PERIODS OF DISUSE” paragraph on page 24.
To ensure the correct functioning of the chiller and to prevent possible problems, it
should only be shut down using the control switch or through the Direct Digital
Controller (DDC) if mounted.
Avoid turning off the GAHP-AR by interrupting the electrical power supply upstream
of the control switch before this has been turned off and the shutdown cycle has
completed.

GAHP-AR – Installation, start-up, use and maintenance manual
6Edition: 2014-08
Do not use the GAHP-AR if any part has been under water. Immediately call a
qualified service technician to inspect the appliance and to replace any part of the
control system and gas control, which has been under water.
Maintenance
Correct and regular maintenance ensures that the GAHP-AR will continue to run properly
and efficiently over time.
Trust the maintenance of the internal components of the GAHP-AR to a Qualified Service
Engineer, who will perform the operations following the manufacturer’s instructions.
For other maintenance operations, go to the “MAINTENANCE” paragraph, page 73.
Any repairs to the GAHP-AR must be done by a Robur authorized Technical Service
Centre (TAC), using only original replacement parts. Not following these regulations could
compromise their functioning and safety, and also void the warranty if still valid.
If the GAHP-AR is sold or transferred to another owner, make sure that this manual is
included in the transaction so that the new owner and any installers may use it for
consultation purposes.
If the GAHP-AR is decommissioned, contact Robur Corporation for its disposal.
1.2 OPERATION OF THE GAHP-AR
GAHP is the acronym for “Gas Absorption Heat Pump”. The GAHP-AR is a high efficiency
reversible air-water heat pump, operating by a water-ammonia absorption cycle and
designed for outdoor use.
The GAHP-AR is able to chill water down to a temperature of 37.4 °F, or to heat it up to
140°F in heat pump mode with a nominal1efficiency of 126%.
The cycle of the GAHP-AR is fed by thermal energy provided by a gas burner, therefore
the required electric energy is limited to driving the fan and pump motors (the only
mechanical moving components of the unit).
The GAHP-AR is fed by natural gas or LPG, and supplied with 208-230 V – 60 Hz single
phase electrical power. The inversion (cooling-heating) is done by a complex dedicated
valve.
The evacuation of combustion products takes place through appropriate exhaust terminal,
located on the side of the appliance (see paragraph “GAHP-AR DIMENSIONS”, page 14),
with outlet in a vertical position.
Operating mode
¾When operating in cooling mode (in summer)
the appliance operates as an absorption chiller, and the heat, taken away from the
cooled environment via the HYDRAULIC CIRCUIT, is dissipated towards the
outside via the air-cooled FINNED COIL.
¾When operating in heating mode (in winter)
the appliance uses the absorption cooling cycle to recover heat from the outside
environment via the FINNED COIL which, added to the heat produced by the
combustion of natural/L.P.G. gas, is transferred into the EXCHANGER and then
1Nominal conditions: external ambient temperature 44.6°F; inlet water temperature 122°F.

Overview and technical specifications section
Ed. 2014-08 7
into the environment to be heated, ensuring efficiency of 126 % (under nominal
conditions).
The GAHP-AR is equipped with the following devices:
•Steel sealed circuit, painted with external epoxy paint.
•Premixed multigas burner with ignition and flame sensing device managed by
electronic control box.
•Steel pipe air exchanger with single-rank fin coil and aluminium fins.
•Titanium stainless steel tube bundle water exchanger, with external insulation.
•Reversal valve on the refrigerant circuit; it switches the unit between heating and
chilling mode.
•Two-way automatic defrosting valve, controlled by microprocessor, allows the fin coil
defrosting.
•Variable (summer operations) air flow helicoidal fan, controlled by microprocessor.
CONTROL AND SAFETY DEVICES
The GAHP-AR is controlled and monitored by the S61 control board through the
peripheral AR10 card. These cards and many other devices compose the control and
safety devices set of the GAHP-AR, listed below:
- S61 control board with integrated microprocessor, with LCD display and encoder;
AR10 peripheral card.
- Plant water flow meter sensor.
- High temperature limit thermostat, manual reset.
- Differential air pressure switch.
- Flue temperature limit switch, automatic reset.
- Sealed circuit safety relief valve.
- Safety by-pass valve, between high and low pressure sealed circuit.
- Antifreeze function for hydronic system.
- Ionization flame control box.
- Double shutter electric gas valve.
- Direct Digital Controller (DDC) with LCD display and knob (encoder), see Figure 2,
page 8.

GAHP-AR – Installation, start-up, use and maintenance manual
8Edition: 2014-08
Figure 1 – S61 control board and AR10 peripheral board
For board operating instructions see the paragraph “ON-BOARD ELECTRONICS”, page
17. The CAN BUS port allows the connection of one or more GAHP-AR to one or more
DDC, Display digital Controller.
The DDC, available as optional, allows a precise control and monitoring on each single
GAHP-AR; a single DDC supports up to 16 GAHP-AR on a single hydraulic plant,
operating them according to the requested thermal load.
Figure 2 – DDC, Direct Digital Controller
If up to do a DDC - GAHP-AR connection, see paragraph “USE OF THE DIRECT
DIGITAL CONTROLLER (DDC)”, page 58.
KEY
A 4 digit DISPLAY for data and codes visualization
B KNOB (encoder) to scroll/select operating data
C CAN PORT for the CAN-BUS cable connection
B
A
C
Electronic Control Board S 61
A
R10
p
eri
p
heral board

Overview and technical specifications section
Ed. 2014-08 9
1.3 TECHNICAL DATA
GAHP-AR – TECHNICAL SPECIFICATIONS
QUANTITY UNITS GAHP-AR
PERFORMANCE RATINGS – HEATING (1)
EXTERNAL AMBIENT OPERATING TEMPERATURE
(DRY BULB / WET BULB) °F 44.6 / 42.8
OUTLET (TO PLANT) WATER TEMPERATURE °F 122.0
HEATING CAPACITY kBtu/hr 120.4
G.U.E. % 126
WATER FLOW (∆T=18 °F) GPM 13.4
PRESSURE DROP (NOMINAL CONDITION) Feet of Head
PSIg
9.80
4.20
PERFORMANCE RATINGS – COOLING (1)
EXTERNAL AMBIENT OPERATING TEMPERATURE °F 95.0
OUTLET (TO PLANT) WATER TEMPERATURE °F 44.6
COOLING CAPACITY kBtu/hr 57.7
G.U.E. % 60
WATER FLOW (∆T=9 °F) GPM 12.8
PRESSURE DROP (NOMINAL CONDITION) Feet of Head
PSIg
10.46
4.50
OPERATIONAL LIMITS – HEATING
EXTERNAL AMBIENT OPERATING TEMPERATURE (DRY BULB)
MAX
MIN
°F
°F
95.0
-20.0
WATER FLOW MAX
MIN
GPM 22.0
6.2
INLET (TO THE UNIT) WATER TEMPERATURE
MAX
MIN
°F
°F
122.0
35.6
OUTLET (TO PLANT) WATER TEMPERATURE
MAX (∆T=27 °F) °F
140.0
OPERATIONAL LIMITS – COOLING
EXTERNAL AMBIENT OPERATING TEMPERATURE
MAX
MIN
°F
°F
120.0
32.0
WATER FLOW MAX
MIN
GPM 14.1
11.0
INLET (TO THE UNIT) WATER TEMPERATURE
MAX
MIN
°F
°F
113.0
42.8
OUTLET (TO PLANT) WATER TEMPERATURE
MIN
°F
37.4
Table 3 - GAHP-AR performance ratings and operational limits.
(1) ALL ILLUSTRATIONS AND SPECIFICATIONS CONTAINED HEREIN ARE BASED ON THE LATEST INFORMATION AVAILABLE AT
THE TIME OF PUBLICATION APPROVAL. ROBUR RESERVES THE RIGHT TO MAKE CHANGES AT ANY TIME WITHOUT NOTICE, IN
MATERIALS, SPECIFICATIONS, AND MODELS OR TO DISCONTINUE MODELS.

GAHP-AR – Installation, start-up, use and maintenance manual
10 Edition: 2014-08
BURNER SPECIFICATIONS
GAS INPUT (HHV) kBtu/hr 95.5
ELECTRICAL RATINGS
REQUIRED VOLTAGE, 60 HZ, SINGLE PHASE (2) V 208 - 230
MINIMUM CIRCUIT AMPACITY (MCA) Unit only A 8.0
MAXIMUM OVER CURRENT PROTECTION (MOCP) A 10.9
TOTAL ELECTRICAL OPERATING CONSUMPTION (NOMINAL) (3) kW 0.75
PHYSICAL DATA
SHIPPING WEIGHT Pounds 883
OPERATING WEIGHT Pounds 838
UNIT WATER VOLUME (4) Gallons 0.79
DIMENSIONS (5) WIDTH
LENGTH
HEIGHT
Inches
331/2
481/2
57
WATER CONNECTIONS (INLET / OUTLET) FPT 1” 1/4
GAS INLET CONNECTION FPT 1/2
HEATER GASES DUCT INTERNAL DIAMETER Inches 31/8
Table 4 - GAHP-AR technical data
(2) UNITS ARE FACTORY-WIRED FOR 208-230 VOLTS OPERATION.
(3) MAY VARY BY ±10% AS A FUNCTION OF BOTH POWER SUPPLY AND ELECTRICAL MOTOR INPUT TOLERANCE.
(4) REFERRED TO A SOLUTION OF QUALITY TAP WATER AND 10% BY VOLUME OF INHIBITED PERMANENT ANTIFREEZE. HIGHER
ANTIFREEZE CONCENTRATIONS MAY BE REQUIRED IN CERTAIN APPLICATIONS. MONO-ETHYLENE GLYCOL CAUSES
CORROSION PHENOMENON IN GALVANIZED METAL PIPES.
(5) FOR GASES DUCT DIMENSIONS SEE FIGURE 3, PAGE 14.

Overview and technical specifications section
Ed. 2014-08 11
HEATING MODE CAPACITY – Btu/hr
OUTLET (TO PLANT) HOT WATER TEMPERATURE
EXTERNAL
AMBIENT
OPERATING
TEMPERATURE
(DRY BULB) 86°F 113°F 122°F 140°F
∆T=18°F ∆T=27°F
-20.0°F 91.1 82.9 82.9 80.9
-13.0°F 92.1 83.9 83.9 81.9
-4.0°F 93.2 85.0 85.0 82.9
5.0°F 97.2 89.4 88.0 85.6
14.0°F 105.4 94.5 92.1 90.1
19.4°F 111.9 100.3 96.9 95.5
35.6°F 123.9 118.7 109.9 102.4
44.6°F 129.3 128.0 1
12 20 0. .4 4 112.6
50.0°F 131.7 131.0 124.2 117.7
59.0°F 134.1 133.4 128.3 122.2
68.0°F 134.8 134.4 129.3 123.9
77.0°F 134.8 134.4 129.7 126.2
Table 5 - Heating mode capacity. Nominal value is in bold type.
CHILLING MODE CAPACITY - Btu/hr
OUTLET (TO PLANT) CHILLED WATER TEMPERATURE
37.4°F 44.6°F 50.0°F
EXTERNAL
AMBIENT
OPERATING
TEMPERATURE
(DRY BULB) ∆T=9°F
59.0°F 64.8 63.8 64.3
68.0°F 63.5 63.5 64.1
77.0°F 60.1 62.4 63.3
86.0°F 54.3 60.7 61.8
95.0°F 44.0 5
57 7. .7 7 59.4
104.0°F 51.2 54.6
113.0°F 46.1
Table 6 - Chilling mode capacity. Nominal value is in bold type.

GAHP-AR – Installation, start-up, use and maintenance manual
12 Edition: 2014-08
Table 7 - Pressure drop – heating mode
GAHP-AR
∆P evaporator
Outlet water temperature
Chilled water flow 37.4°F 44.6°F 50.0°F
GPM ∆P
ft of Head
∆P
ft of Head
∆P
ft of Head
11.01 8.55 8.11 7.84
11.45 9.15 8.67 8.39
11.89 9.77 9.25 8.96
12.33 10.40 9.85 9.54
12.77 11.05 10.46 10.15
13.21 11.71 11.08 10.76
13.65 12.38 11.72 11.40
14.09 13.07 12.38 12.04
Table 8 - Pressure drop – chilling mode
GAHP-AR
∆P condenser/absorber
Outlet water temperature
Hot water flow 122.0°F 104.0°F 86.0°F
GPM ∆P
ft of Head
∆P
ft of Head
∆P
ft of Head
6.60 3.05 3.08 3.15
7.04 3.30 3.32 3.35
7.48 3.58 3.62 3.65
7.93 3.89 3.98 4.05
8.37 4.25 4.35 4.42
8.81 4.64 4.76 4.86
9.25 5.05 5.19 5.28
9.69 5.50 5.66 5.77
10.13 5.96 6.18 6.29
10.57 6.45 6.66 6.83
11.01 6.95 7.16 7.39
11.45 7.47 7.68 7.97
11.89 7.99 8.21 8.57
12.33 8.52 8.76 9.18
12.77 9.06 9.32 9.80
13.21 9.59 9.90 10.43
13.65 10.12 10.50 11.07
14.09 10.64 11.11 11.72
14.53 11.36 11.81 12.60
14.97 11.98 12.48 13.35
15.41 12.63 13.17 14.12
15.85 13.29 13.87 14.91
16.29 13.97 14.60 15.72
16.73 14.67 15.35 16.55
17.17 15.39 16.11 17.40
17.61 16.13 16.90 18.27
18.05 16.88 17.70 19.16
18.49 17.65 18.53 20.07
18.93 18.44 19.37 21.00
19.37 19.25 20.23 21.94
19.81 20.08 21.11 22.91
20.25 20.92 22.01 23.90
20.69 21.78 22.93 24.90
21.13 22.66 23.87 25.93
21.57 23.56 24.82 26.97
22.01 24.48 25.80 28.03

Overview and technical specifications section
Ed. 2014-08 13
Graph 1 - Pressure drop – heating mode (see Table 7)
Graph 2 - Pressure drop – chilling mode (see Table 8)
6
8
10
12
14
11 12 13 14
37.4°FOutle
t
44.6°FOutle
t
50.0°FOutle
t
PRESSURE DROP
–
CHILLING MODE
WATER FLOW - GPM
∆P
–
FEET OF HEAD
3
6
9
12
15
18
21
24
27
6.6 8.6 10.6 12.6 14.6 16.6 18.6 20.6
86°F Outlet
104°F Outlet
122°F Outlet
WATER FLOW - GPM
∆P
–
FEET OF HEAD
PRESSURE DROP
–
HEATING MODE

GAHP-AR – Installation, start-up, use and maintenance manual
14 Edition: 2014-08
1.4 GAHP-AR DIMENSIONS
GAHP-AR external dimensions – (*) vibration damping positions
38-1
2" (*)
33-1
2"
27-3
8" (*)
48-1
2"
60-7
8"
50-1
2"
10-1
2"
4"
5-7
8"
50-3
4"
Figure 3 – GAHP-AR external dimensions.
GAHP-AR service plate dimensions
Figure 4 – GAHP-AR service plate dimensions. Some details were removed for clarity.
6-1
2"
12"
7-7
8"
5-7
8"
7-1
8"
4-1
4"
LEGEND
A – WATER OUTLET (TO PLANT) Ø 1” 1/4 FPT
B – WATER INLET (TO THE UNIT) Ø 1” 1/4 FPT
G – GAS INLET Ø 1/2FPT
E – ELECTRICAL KNOCKOUTS Ø 7/8
A
B
G
E

End user section
Ed. 2014-08 15
SECTION 2 END USER
In this section you will find all the indications necessary for the activation, regulation and
control of operation of the appliance via the board present in the electrical panel.
2.1 ACTIVATION (AND DEACTIVATION) OF THE APPLIANCE
Efficient operation and long life of the appliance depend largely on correct use!
If the appliance is connected to a Direct Digital Controller (DDC) and the DDC is in
controller mode, activation and control of the appliance will occur exclusively by
operating the DDC. In this case, refer to the manual supplied with it.
If the appliance is not connected to a DDC, it may be activated and deactivated only by
means of the on/off commands provided by the electrical installation technician.
According to requirements, these on/off commands may be:
- An on/off switch (CS, consent switch) for activation and deactivation of the
appliance. This switch may be an on/off button, an ambient thermostat, a
programmable timer, or one or more clean contacts controlled by another process. For
details about the type of on/off command installed, contact the plant’s electrical
installation technician.
- A summer/winter selector switch (W/Y), for selecting the operating mode of the
appliance (cooling or heating).
Activation: the on/off commands are essential.
Do not switch the appliance on or off by connecting it to or disconnecting it from the
power supply directly, as this may be a source of danger and in any case damage
the appliance or the plants connected to it.
Before activating the appliance, check that:
- the gas valve is open;
- the appliance is powered electrically: the general electrical switch must be in the “ON”
position;
- the installation technician has ensured that the hydraulic circuit is supplied in the
correct conditions.
If these conditions are satisfied, it is possible to proceed with activation.
ACTIVATION
Select the operating mode required (cooling or heating) by means of the summer/winter
selector switch, if the mode desired is not already selected.
Switch on the appliance by means of the on/off command (placing it in the "ON" position).

GAHP-AR – Installation, start-up, use and maintenance manual
16 Edition: 2014-08
During operation of the appliance, the summer/winter switch (from summer to
winter operation and vice versa, or so-called "cycle inversion") may require a
maximum of 11 minutes from the time this inversion is invoked by the user.
DEACTIVATION
Switch off the appliance via the on/off command (placing it in the "OFF" position).
the shutdown cycle takes approximately 10 minutes to complete.
Visualization and clearing of operating codes
Operating codes can be generated by the electronic board or by the DDC (if connected to
the appliance).
If these codes arise, it is necessary to follow the instructions in paragraph "WARNINGS
AND ERRORS" on page 90, provided in the APPENDIX, on page 89.
The operating codes generated by the electronic board are visualized on its display and
may also be visualized on the display of the DDC (if fitted).
Operating codes generated by the electronic board can be cleared through the board itself
or from the DDC (if fitted or where possible).
For a description of operating codes generated by the electronic board and how to
clear them, refer to the list of operating codes contained in paragraph “TABLE OF
OPERATING CODES (firmware release 3.027)”, on page 91.
The electronic board (see Figure 1, page 8) is located inside the electrical panel of
the appliance and the display may be viewed through the viewing hole on the front
panel of the unit itself.
Operating codes generated by the DDC:
The operating codes generated by the DDC may be viewed only on the display of
the DDC, and may only be cleared via the DDC.
Operating codes generated by the electronic board during the activation phase of
the appliance (see “TABLE OF OPERATING CODES (firmware release 3.027), page
91).
If the appliance remains inactive for a prolonged period, it is possible that air is present in
the gas pipes. In this case, activation fails and the appliance reports the operating code:
"U612" - on the display, indicating (temporary) arrest of the flame control unit. After a short
interval of time, it automatically begins the activation sequence again. If the code "U612”
persists after three attempts to start the appliance, the appliance flame control unit is
arrested and the display shows a new operating code "E612" – indicating arrest of the
flame control unit. In this case reset is not automatic.
To restore operation of the appliance, carry out a reset of the flame control unit via menu
2 of the electronic board: the procedure is illustrated in Paragraph 2.4, on page 21. After it
is reset, the appliance will make a new attempt to activate.