Envision NSKW 06, NSKW 08, NSKW 12, NSKW 17 Installation Manual
NSKW 06 to 17 kW
Geothermal Hydronic Heat Pump - 50 Hz
Installation Information
Water Piping Connections
Electrical Data
Startup Procedures
Preventive Maintenance
NSKW Installation Manual
IM1066WN 05/15
Table of Contents
Model Nomenclature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
BS EN 14511-2 Performance Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Legend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
General Installation Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Dimensional Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Physical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
NSKW INSTALLATION MANUAL
Water Quality
Field Connected Water Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-10
Potable Water Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-12
Hydronic Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-14
Accessories and Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Electrical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-17
Wiring Schematics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-21
Heat Pump Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
External Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23-24
Converting to a Dedicated Cooling Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Unit Startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Standard Board - Control Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27-28
Standard Control - Panel Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29-30
Optional Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31-35
Reference Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Pressure Drop. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Operating Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Flow Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Thermistor Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Operating Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Antifreeze Correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Troubleshooting Guideline for Refrigerant Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Heating and Cooling Cycle Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Startup and Troubleshooting Form . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43-44
Preventive Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Service Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
NSKW INSTALLATION MANUAL
Model Nomenclature
1-4
NSKW
Model
NSKW = Envision Series 50Hz
Hydronic Heat Pump
Capacity (kW Output)
06
08
12
17
Operation
H = Heating Only
R = Reversible
Voltage
6 = 220-240/50/1
7 = 380-420/50/3
Hot Water Option
0 = No Hot Water Generation, No IntelliStart
2 = Hot Water Generation, No IntelliStart (12-17)
3 = No Hot Water Generation, IntelliStart
5 = Hot Water Generation, IntelliStart (12-17)
7R869010211C12C13-14SS15
5-6
08
A
Vintage
A = 08-17
B = 06
Future Option
SS = Standard Option
Load Coax
C = Copper
N = Cupronickel
Source Coax
C = Copper
N = Cupronickel
Controls Option
2 = Standard Board
4 = FX10 without communication
5 = FX10 with Open N2 Com Card
6 = FX10 with LonWorks card Com Card
7 = FX10 with BACnet Com card
8 = FX10 without communication, with User Interface
9 = FX10 with Open N2 Com Card, with User Interface
0 = FX10 with Lonworks Com card, with User Interface
3 = FX10 with BACnet Com card, with User Interface
1
NOTES: Hot Water Generation (HWG) only available on NSKW12-17 and requires a field installed external pump
1
- 06 heating only models are available only with copper double wall vented load coax.
All Envision Series NSKW product is safety tested to CE standards and
performance tested in accordance with standard BS EN 14511-2.
4
BS EN 14511-2 Performance Ratings
Heating Performance
B0/W35 W10/W35 B0/W45 B5/W35 W10/W45
Capacity
Model
All ratings based upon 220V operation
All ratings based on new heat pump with clean heat exchangers
Output
06
5.80 3.80 1.53 7.30 4.80 1.52 5.50 2.90 1.90 6.60 4.30 1.54 7.10 3.70 1.92
08
8.30 4.20 1.98 10.6 5.30 2.00 8.00 3.20 2.50 9.50 4.80 1.98 10.2 4.10 2.49
12
17
COP
kW
11.6 4.20 2.80 14.4 5.30 2.72 11.3 3.20 3.53 13.3 4.80 2.77 14.2 4.10 3.46
16.6 3.70 4.49 21.4 4.70 4.55 15.9 2.90 5.50 19.0 4.30 4.42 20.4 3.70 5.51
Cooling Performance
Model
All ratings based upon 220V operation
All ratings based on new heat pump with clean heat exchangers
06
08
12
17
Capacity
Output kW
4.00 2.80 1.43 5.90 4.10 1.44 8.10 5.60 1.45
6.10 3.00 2.03 9.00 4.40 2.05 12.4 6.00 2.07
8.20 2.90 2.82 12.0 4.30 2.80 16.6 5.80 2.86
11.2 2.60 4.30 16.4 3.80 4.32 22.7 5.20 4.37
Power
Capacity
Input
W30/B0 W30/W12 W30/W23
EER (W/W)
kW
Output
COP
kW
Power Input kW Capacity
Power
Capacity
Input
kW
Output kW
Output
kW
COP
EER (W/W)
Power
Capacity
Input
Output
kW
Power Input kW Capacity
COP
kW
Output kW
NSKW INSTALLATION MANUAL
Power
Input
kW
Capacity
Output
kW
EER (W/W)
COP
Power
Input
kW
9/26/11
Power Input
kW
9/26/11
Legend
ABBREVIATIONS AND DEFINITIONS:
COP = coefficient of performance
EER = cooling energy efficiency (TC/kW)
ELT = entering load fluid temperature
EST = entering source fluid temperature to heat pump
FLA = full load amps
FtHd = pressure drop in feet of head
gpm = US gallon per minute
HC = heating capacity in kW
HE = heat of extraction in kW
HR = heat rejected in kW
kPa = kilopascal
kW = kilowatt
CONVERSIONS:
x°F = (x - 32)/1.8°C
1 bar = 100 kPa
1 gpm = 0.0631 L/s
L/s = liters per second
LLT = leaving load fluid temperature from heat pump
LRA = locked rotor amps (starting current)
LST = leaving source fluid temperature from heat pump
LWPD = load heat exchanger water pressure drop
MCC = maximum continuous current
PD = pressure drop
psi = pressure drop in pounds per square inch
P/T = Pressure/Temperature
RLA = run load amps
TC = total cooling capacity in kW
W = Watt
1 US Gallon = 3.785412 L
1 Btu/h = 0.29037 W
5
NSKW INSTALLATION MANUAL
General Installation Information
Safety Considerations
Installing and servicing air conditioning and heating
equipment can be hazardous due to system pressure and
electrical components. Only trained and qualified service
personnel should install, repair or service heating and air
conditioning equipment. When working on heating and
air conditioning equipment, observe precautions in the
literature, tags and labels attached to the unit and other
safety precautions that may apply.
Follow all safety codes. Wear safety glasses and work
gloves. Use quenching cloth for brazing operations. Have
fire extinguisher available for all brazing operations.
NOTE: Before installing, check voltage of unit(s) to ensure
proper voltage.
WARNING: Before performing service or
maintenance operations on the system, turn off
main power switches to the unit. Electrical shock
could cause serious personal injury.
Process Water Applications
For process water applications, it is recommended that
a secondary load heat exchanger be installed to prevent
corrosion to the unit’s primary coaxial coil. In situations
where scaling could be heavy or where biological growth
such as iron bacteria will be present, a closed loop system
is recommended. Over a period of time, ground water unit
heat exchanger coils may lose heat exchange capability
due to a buildup of mineral deposits. These can be cleaned
only by a qualified service mechanic as special pumping
equipment and solutions are required.
WARNING: To avoid equipment damage, do not
leave the system filled in a building without heat
during cold weather, unless adequate freeze
protection levels of antifreeze are used. Heat
exchangers do not fully drain and will freeze
unless protected, causing permanent damage.
Unit Location
Provide sufficient room to make water and electrical
connections. If the unit is located in a confined space,
provisions must be made for unit servicing. Locate the
unit in an indoor area that allows easy removal of the
access panels and has enough space for service personnel
to perform maintenance or repair. These units are not
approved for outdoor installation and, therefore, must be
installed inside the structure being conditioned. Do not
locate units in areas subject to freezing conditions.
WARNING: Do not store or install units in
corrosive environments or in locations subject
to temperature or humidity extremes (e.g. attics,
garages, rooftops, etc.). Corrosive conditions and
high temperature or humidity can significantly
reduce performance, reliability, and service life.
Mounting Units
Units should be mounted level on a vibration absorbing pad
slightly larger than the base to provide isolation between
the unit and the floor. It is not necessary to anchor the unit
to the floor. Allow access to the front, back, and side access
panels for servicing.
Moving and Storage
Move units in the normal “Up” orientation as indicated by
the labels on the unit packaging. When the equipment
is received, all items should be carefully checked against
the bill of lading to ensure that all crates and cartons
have been received in good condition. Examine units for
shipping damage, removing unit packaging if necessary
to properly inspect unit. Units in question should also
be internally inspected. If any damage is observed, the
carrier should make the proper notation on delivery receipt
acknowledging the damage. Units are to be stored in a
location that provides adequate protection from dirt, debris
and moisture.
DWP`ObW]\>OR;]c\bW\U
6
Dimensional Data
NSKW INSTALLATION MANUAL
A
C
B
Z
Y
NOTE: Plastic front panel extends 3.56 cm beyond front of cabinet.
Overall Cabinet Water Connections
Model
06
08
12
17
Model
06
08
12
17
NOTE: Plastic front panel extends 3.56 cm beyond front of cabinet.
ABCDE FGH I
Depth Height Width
cm. 59.7 66.3 49.5 25.4 56.4 25.4 56.4 - - 25.4 mm 25.4 mm - 4 0.6 3 6.1 36 .1
cm. 78.7 66.5 55.9 5.3 49.8 5.3 49.8 60.7 60.7 25.4 mm 25.4 mm 12.7 mm 43.4 37.6 43.4
cm. 78.7 66.5 55.9 5.6 52.3 5.6 52.3 60.7 60.7 31.8 mm 31.8 mm 12.7 mm 43.4 37.6 43.4
cm. 78.7 66.5 55.9 6.1 58.4 6.1 58.4 52.3 52.3 31.8 mm 31.8 mm 12.7 mm 43.4 37.6 43.4
MNOP QR S T UVWXYZ
Load
Liquid In
cm. 6.1 6.1 6.1 6.1 - - 8.9 7.4 37.8 6.6 5.3 4.4 7.4 10.4
cm. 4.1 7.0 7.0 4.1 5.1 4.6 12.2 12.2 43.4 7.0 37.8 12.2 12.2 43.4
cm. 4.6 9.1 9.1 4.6 5.3 4.6 12.2 12.2 43.4 7.1 37.8 12.2 12.2 43.4
cm. 4.6 10.2 10.2 4.6 10.7 3.6 12.2 12.2 43.4 7.1 37.8 12.2 12.2 43.4
Load
Liquid
Out
X
Source
Liquid In
W
Load
Liquid
In
Source
Liquid
Load
Liquid
Out
Water Connections Electrical Knockouts
HWG In
Out
Source
Liquid
In
HWG
Out
Source
Liquid
Out
Power
Supply
HWG In
Voltage
V
Low
U
HWG
Out
Load
Water
Side
Power
Supply
I
FPT
E
L
Side
Power
Supply
N
R
D
Source
Water
FPT
S
Pump
M
HWG
Water
FPT
Ext
T
Q
P
H
G
J
K
F
O
8/09/13NOTE: Plastic front panel extends 1.4" (3.56 cm) beyond front of cabinet.
Electrical Knockouts
JKL
1/2 in.
cond
Low
Voltage
Ext
Pump
3/4 in.
Power
Supply
cond
Ext
Pump
3/4 in.
cond
Power
Supply
Power
Supply
8/6/10
Physical Data
Model 06 08 12 17
Compressor (1 each) Scroll
Factory Charge R410A, oz [kg] 58 [1.64] 70 [1.98] 68 [1.93] 110 [3.12]
Coax & Piping Water Volume - gal [l]* 0.89 [3.38] 1.0 [3.94] 1.4 [5.25] 1.6 [6.13]
Weight - Operating, lb [kg] 225 [102.1] 290 [131.5] 325 [147.4] 345 [156.5]
Weight - Packaged, lb [kg] 247 [112.0] 305 [138.3] 340 [154.2] 360 [163.3]
Note: * Source or load side only 3/25/15
7
NSKW INSTALLATION MANUAL
Water Quality
General
NSKW heat pumps may be successfully applied in a wide
range of residential and light commercial applications. It
is the responsibility of the system designer and installing
contractor to ensure that acceptable water quality is
present and that all applicable codes have been met in
these installations. Failure to adhere to the guidelines in the
building’s piping system that the designer may need to take
into consideration when deciding the parameters of the
water quality.
If an antifreeze or water treatment solution is to be used,
the designer should confirm it does not have a detrimental
effect on the materials in the system.
water quality table could result in loss of warranty.
Contaminated Water
Water Treatment
Do not use untreated or improperly treated water.
Equipment damage may occur. The use of improperly
treated or untreated water in this equipment may result in
scaling, erosion, corrosion, algae or slime. The services of a
qualified water treatment specialist should be engaged to
determine what treatment, if any, is required. The product
warranty specifically excludes liability for corrosion,
erosion or deterioration of equipment.
The heat exchangers and water lines in the units are copper
or cupronickel tube. There may be other materials in the
Water Quality Guidelines
Material Copper 90/10 Cupronickel 316 Stainless Steel
pH Acidity/Alkalinity
Scaling
Corrosion
Iron Fouling
(Biological Growth)
Erosion
NOTES: Grains = ppm divided by 17
mg/L is equivalent to ppm
Calcium and
Magnesium Carbonate
Hydrogen Sulfide
Sulfates Less than 125 ppm Less than 125 ppm Less than 200 ppm
Chlorine Less than 0.5 ppm Less than 0.5 ppm Less than 0.5 ppm
Chlorides Less than 20 ppm Less than 125 ppm Less than 300 ppm
Carbon Dioxide Less than 50 ppm 10 - 50 ppm 10 - 50 ppm
Ammonia Less than 2 ppm Less than 2 ppm Less than 20 ppm
Ammonia Chloride Less than 0.5 ppm Less than 0.5 ppm Less than 0.5 ppm
Ammonia Nitrate Less than 0.5 ppm Less than 0.5 ppm Less than 0.5 ppm
Ammonia Hydroxide Less than 0.5 ppm Less than 0.5 ppm Less than 0.5 ppm
Ammonia Sulfate Less than 0.5 ppm Less than 0.5 ppm Less than 0.5 ppm
Total Dissolved Solids (TDS) Less than 1000 ppm 1000 - 1500 ppm 1000 - 1500 ppm
LSI Index +0.5 to -0.5 +0.5 to -0.5 +0.5 to -0.5
Iron, FE
Bacterial Iron Potential
Iron Oxide
Suspended Solids
Threshold Velocity
(Fresh Water)
2
+ (Ferrous)
Less than 0.5 ppm (rotten egg
smell appears at 0.5 ppm)
Less than 1 ppm, above this
level deposition will occur
Less than 10 ppm and filtered
for max. of 600 micron size
7 - 9 7 - 9 7 - 9
(Total Hardness)
less than 350 ppm
< 0.2 ppm < 0.2 ppm < 0.2 ppm
< 1.8 m/sec < 1.8 m/sec < 1.8 m/sec
In applications where the water quality cannot be held to
prescribed limits, the use of a secondary or intermediate
heat exchanger is recommended to separate the unit from
the contaminated water.
The following table outlines the water quality guidelines
for unit heat exchangers. If these conditions are exceeded,
a secondary heat exchanger is required. Failure to supply
a secondary heat exchanger where needed will result in a
warranty exclusion for primary heat exchanger corrosion or
failure.
(Total Hardness)
less than 350 ppm
10 - 50 ppm Less than 1 ppm
Less than 1 ppm, above this
level deposition will occur
Less than 10 ppm and filtered
for max. of 600 micron size
(Total Hardness)
less than 350 ppm
Less than 1 ppm, above this
level deposition will occur
Less than 10 ppm and filtered
for max. of 600 micron size
2/22/12
8
Field Connected Water Piping
NSKW INSTALLATION MANUAL
General
Each unit is equipped with captive female pipe thread (FPT)
water connections to eliminate ‘egg-shaping’ from use of
a backup wrench. For making the water connections to
the unit, a Teflon tape thread sealant is recommended to
minimize internal fouling of the piping. Do not over tighten
connections. All supply and return water piping should be
insulated to prevent excess condensation from forming on
the water lines.
NOTES: 1) WaterFurnace recommends a male national pipe
thread (NPT) to British standard pipe fitting (BSPF) to
adapt to NSKW water connections. 2) Units are factory runtested using propylene glycol. Prior to connecting piping
to unit, thoroughly flush heat exchangers.
The piping installation should provide service personnel with
the ability to measure water temperatures and pressures.
The water lines should be routed so as not to interfere with
access to the unit. The use of a short length of high pressure
hose with a swivel type fitting may simplify the connections
and prevent vibration. Optional stainless steel hose kits are
available as an accessory item.
Before final connection to the unit, the supply and return
hose kits must be connected, and the system flushed
to remove dirt, piping chips and other foreign material.
Normally, a combination balancing and close-off (ball) valve
is installed at the return, and a rated gate or ball valve is
installed at the supply. The return valve can be adjusted to
obtain the proper water flow. The valves allow the unit to be
removed for servicing.
The proper water flow must be delivered to each unit
whenever the unit heats or cools. To assure proper flow,
the use of pressure/temperature ports is recommended
to determine the flow rate. These ports should be located
adjacent to the supply and return connections on the unit.
The proper flow rate cannot be accurately set without
measuring the water pressure drop through the refrigerantto-water heat exchanger (See Pressure Drop Table for water
flow and pressure drop information). Normally about 0.054
L/s per kW flow rate of cooling capacity (0.040 L/s per kW
minimum) is needed. Both source as well as load fluid piping
must be at least as large as the unit connections on the heat
pump (larger on long runs).
Never use flexible hoses of a smaller inside diameter than that
of the water connection on the unit and limit hose length to
3.05 m per connection. Check carefully for water leaks.
CAUTION: Water piping exposed to outside
temperature may be subject to freezing.
Open Loop Well Water Systems
Always maintain water pressure in the heat exchanger by
placing water control valves at the outlet of the unit. Use
a closed bladder type expansion tank to minimize mineral
deposits. Ensure proper water flow through the unit by
checking pressure drop across the heat exchanger and
comparing it to the figures in the pressure drop table.
Normally, about 0.038 L/s per kW flow rate of cooling
capacity is needed in open loop systems, 0.029 L/s per kW
minimum if entering source temperature is above 10°C.
Some water control valves draw their power directly from
the unit’s 24V transformer and can overload and possibly
burn out the transformer. Check total VA draw of the water
valve(s) and ensure it is under 40 VA.
Discharge water from a heat pump can be disposed of in
various ways depending on local building codes (i.e. recharge
Typical Open Loop Installation
Line Voltage
Disconnect
Load Liquid
Connections
Shut-off Valve
(to isolate solenoid
valve while acid
flushing)
Rubber Bladder
Expansion Tank
Flow Regulator Valve
Solenoid
Valve
Boiler Drains for
HX Flushing
P/T Plugs
Vibration Absorbing
Mesh or Air Pad
Water Out
Water In
Shut-off
Valve
NOTE: Valves and boiler drains must be installed
so the heat exchanger can be acid flushed.
9
NSKW INSTALLATION MANUAL
Field Connected Water Piping cont.
well, storm sewer, drain field, adjacent stream or pond,
etc.). Most local codes restrict the use of sanitary sewer for
disposal. Consult your local building and zoning departments
to ensure compliance in your area.
Earth Coupled Systems with Flow Center
Once piping is completed between the unit, flow center
and the earth loop, final purging and charging of the loop is
needed. A pump capable of 14 m
3
/hr @ 25 meters of head
is needed to achieve adequate flow velocity in the loop to
purge air and dirt particles from the loop itself. Antifreeze
solution is used in most areas to prevent freezing. Maintain
the pH in the 7.6-8.2 range for final charging.
Flush the system adequately to remove as much air as
possible. Then, pressurize the loop to a static pressure of
345-517 kPa. This is normally adequate for good system
operation. Ensure that the flow center provides adequate
flow through the unit by checking pressure drop across the
heat exchanger and by comparing it to the figures shown
in the Pressure Drop tables. Usually, 0.054 L/s per kW or
minimum 0.040 L/s per kW of cooling capacity is needed in
closed loop earth-coupled applications.
Ground Loop Design and Installation
This instruction manual does not cover the design and
installation of the ground loop system. WaterFurnace
recommends that all ground loops are designed using
Typical Closed Loop Earth Coupled Installation
Earth Coupled Loop
Piping with Insulation
Line Voltage
Disconnect
Unit Connector Kits
with Insulation
P/T Plugs
Vibration Absorbing
Mesh or Air Pad
GeoLink
Load Liquid
Connections
TM
Design Studio (GDS) or another commercial
software package. Installers shall follow the guidelines
detailed in Microgeneration Certification Scheme (MCS)
Installation Standard MIS 3005 for designing ground loop
collectors. Additional guidance on ground collectors is
provided by International Ground-Source Heat Pump
Association (IGSHPA).
Potable Water Systems
NSKW06-17 kW heat pumps can be equipped with a
double-wall vented coaxial heat exchanger capable of hot
water generation (HWG). An optional factory-installed hot
water generator coil may be provided with NSKW08-17. The
temperature of the hot water produced by the heat pump
cannot be adjusted and will vary with the inlet temperature.
WaterFurnace recommends the use of a properly sized
buffer tank equipped with supplemental electric immersion
heaters in conjunction with all NSKW models used in an
HWG application. Immersion heaters must be capable
of heating the water to 60°C at a regular time interval
to prevent the build-up of bacteria such as Legionella.
Installations must meet minimum requirements outlined in
UK Domestic Heating Compliance Guide.
CAUTION: Hot water in excess of 60°C can cause
scalding.
Hot Water Generator Connections
The heat reclaiming hot water generator coil is vented double-
wall copper construction and is suitable for potable water. To
maximize the benefits of the hot water generator a minimum
50-gallon water heater is recommended. For higher demand
applications, use an 80-gallon water heater as shown below or
two 50-gallon water heaters connected in a series. A geo storage
tank should not be used in this application unless it is plumbed
in a series with an electric water heater. The geo storage tank is
equipped with a single 4500 Watt element and will not be able
to provide adequate water heating if used as a standalone water
heater. Electric water heaters are recommended. Make sure all
local electrical and plumbing codes are met for installing a hot
water generator. The Envision NSKW is not supplied with an
internal circulator.
10
Potable Water Systems cont.
Suggested Domestic Water Heater Hookup
207 kPa
RELIEF VALVE
Back Flow Preventer /
Pressure Relief Valve
Pressure
Gauge
Vent
Expansion
Tank
Air
Air
Separator
LOAD PUMP
NSKW INSTALLATION MANUAL
HYDRONIC
LOAD
Vent Valve or
P/T Port**
Dielectric
Unions
GEO
STORAGE
TANK
Dip Tube
Dielectric
Unions
Ball Valve
NOTES:
* A 207 kPa pressure relief valve (Part No: SRV30) should be used in
hydronic applications.
** Vent valve or Pressure/Temperature port at highest point in return line prior to ball valve.
NOTES:
1) Unions and valves must be installed so that acid flushing
of the heat exchanger is possible.
2) Route thermistor wires to NSKW. Remove yellow
thermistor wires on TB 3 and 4 from control box and
connect thermistor wires from geothermal storage tank.
Set the pump sampling (PS) in the set up of the control
board to continuously (C) sampling (reference Note 5 in
the Wiring Schematic).
P/T
Ports
Ball Valve
FROM
HWG
HWG
WaterFurnace
NSKW Series
TO
PUMP
Source OUT
P/T
Ports
Source IN
HOT
(Piped in
series to
an electric
water heater)
COLD
DOMESTIC
11
NSKW INSTALLATION MANUAL
Potable Water Systems cont.
Alternate Hot Water Installation with
Direct Coupling to a Double Wall Unit
Dielectric
Unions
HOT
COLD
LOOP FIELD
FLOW CENTER
Dielectric
Unions
Ball Valve
WaterFurnace
GEOTANK
NOTES:
1) Unions and valves must be installed so that acid flushing
of the heat exchanger is possible.
2) Make sure there is not a check valve in the diptube of the
tank.
3) Route thermistor wires to NSKW. Remove yellow
thermistor wires on TB 3 and 4 from control box and
connect thermistor wires from geothermal storage tank.
Set the pump sampling (PS) in the set up of the control
board to continuously (C) sampling (reference Note 5 in
the Wiring Schematic).
P/T
Ports
Ball Valve
WaterFurnace
NSKW06 (Heating Only)
with Double Wall Load Coax
P/T
Ports
12
Hydronic Section
NSKW INSTALLATION MANUAL
General guidelines are shown below for component
selection and design/installation criteria for the piping
system. Local codes supersede any recommendations in
this manual.
Shut Off/Flow Regulation Valves
Use full port ball valves or gate valves for component
isolation. If valves are going to be used frequently, ball
valves are recommended. Globe valves are designed for
flow regulation. Always install globe valves in the correct
direction (fluid should enter through the lower body
chamber).
Check valves
Swing check valves must be installed in the horizontal
position with the bonnet of the valve upright. Spring check
valves can be mounted in any position. A flow check valve
is required to prevent thermo-siphoning (or gravity flow)
when the circulator pump is off or when there are two
circulators on the same system.
Storage (Buffer) Tank
A buffer tank is required for all hydronic heating systems
using Envision NSKW heat pumps. The tank should be sized
to provide 2 gallons [7.6 L] of storage capacity for every
300W of nominal heat pump capacity.
Pressure Relief Valve
Most codes require the use of a pressure relief valve if a
closed loop heat source can be isolated by valves. Even
if local code does not require this device, WaterFurnace
recommends its installation. If the pressure relief valve in
the buffer tank is not already rated at 207 kPa maximum
pressure, one must be installed. The pressure relief valve
should be tested at start up for operation. Note that the
waste pipe must be at least the same diameter as the valve
outlet (never reduce), and valves may not be added to this
pipe. The bottom of the pipe must terminate at least 15 cm
above the floor. If the piping is connected to a drain, there
must be an air gap.
Pressure Reducing Valves or Feed Water Valves
This valve lowers the pressure from the make-up water line
to the system. Most are adjustable and directional. A “fast
fill” valve is required for initial filling of the system. Some
have screens, which must be cleaned after the initial filling.
If there is a restriction in the screen, the system could go to
0 kPa, potentially causing pumps(s) failure. A valve should
be installed on each side of the pressure reducing valve for
servicing. Both valves should have tags reading “Do not
shut this valve under normal operation – service valve only.”
Expansion Tanks
Expansion tanks are required on hydronic systems to help
absorb the pressure swings as the temperature in the
system fluctuates.
Elbows/Tees
Long radius elbows or two 45° elbows will lower pressure
drop. Standard tees have a greater restriction on the “T”
portion than tees designed with angled outlet ports.
Antifreeze
Antifreeze is required if any of the piping system is located
in areas subject to freezing.
Dielectric Unions
Dielectric unions are recommended whenever connecting
two dissimilar metals to one and other to prevent electrogalvanic corrosion.
When using the various types of hydronic heat distribution
systems, the temperature limits of the geothermal system
must be a major consideration. In new construction, the
distribution system can easily be designed with the
temperature limits in mind. In retrofits, care must be
taken to address the operating temperature limits of the
existing distribution system. The maximum storage tank
temperature for the Envision NSKW is 54.4°C. Typical in
floor radiant systems require much lower temperatures,
typically 37.8°-46.1°C, which is ideal for the Envision NSKW.
Backflow Prevention Check Valves
Most codes require backflow prevention check valves.
Note that a single check valve is not equal to a backflow
prevention check valve. Even if local code does not require
this device, WaterFurnace recommends its installation. This
is particularly important if the system will use antifreeze.
13
NSKW INSTALLATION MANUAL
Hydronic Section cont.
Open the screw 2 turns only in the end of the pump motor
(if Grundfos
®
pumps are used) to allow trapped air to be
discharged and to ensure the motor housing has been
flooded.
Route thermistor wires to NSKW. Remove yellow thermistor
wires on TB 3 and 4 from control box and connect
thermistor wires from geothermal storage tank. Set the
pump sampling (PS) in the set up of the control board to
continuously (C) sampling (reference Note 5 in the Wiring
Schematic).
Adequate rate of flow is very important to system
performance and long term reliability. Follow the guidelines
for recommended flow and pipe sizing in the NSKW
recommendations table.
207 kPa
RELIEF VALVE
Back Flow Preventer /
Pressure Relief Valve
Pressure
Gauge
Air
Vent
Expansion
Tank
WaterFurnace Geothermal Storage Tank Thermostat
and Thermistor
NSKW
Yellow Thermistor Wires Connected to TB (3 and 4) on
NSKW Control Board
LOAD PUMP
Air
Separator
HYDRONIC
LOAD
Vent Valve or
P/T Port**
Dielectric
Unions
GEO
STORAGE
TANK
Dip Tube
Dielectric
Unions
Ball Valve
NOTES:
* A 207 kPa pressure relief valve (Part No: SRV30) should be used in
hydronic applications.
** Vent valve or Pressure/Temperature port at highest point in return line prior to ball valve.
Ball Valve
14
P/T
Ports
FROM
HWG
HWG
WaterFurnace
NSKW Series
TO
PUMP
Source OUT
P/T
Ports
Source IN
HOT
(Piped in
series to
an electric
water heater)
COLD
DOMESTIC
Accessories and Options
Geo Storage Tank Dimensions
NSKW INSTALLATION MANUAL
°
3
0
0
3
°
From Geo
PRIMARY ANODE
99 cm - 80 Gallon
106.7 cm - 119 Gallon
HOT OUTLET
w/35.6 cm SECONDARY ANODE
Approx. 2.54 cm
T & P
VALVE
HEIGHT
90.8 cm
To Geo 150 cm Dip Tube
20.3 cm
COLD INLET
132.0 cm DIP TUBE
Yellow Wire attached
to Thermistor or Thermostat
for Top Exit
Element Location
Lower Sensor Thermistor (12P541-01)
to be used by Water to Water Units
Optional “From Geo” Connection
13.3 cm
Model
Number
GEO-STORAGE-80
GEO-STORAGE-120
DRAIN VALVE
Gallon [Liter]
Capacity
80 [303] 4500 1 16 160.6 61.0 92.5
119 [450] 4500 1 16 160.6 71.1 141.1
Element
Wattage
(240 Volt)
DIAMETER
Number
of
Elements
R
Value
Lower Thermostat
Dimensions in cm
Height Diameter
Approx Shipping
Weight kg
15
NSKW INSTALLATION MANUAL
Electrical Data
Model
06
08
12
17
Notes:
* - With optional IntelliStart, Type D MCB recommended
NSKW Control Box
Optional IntelliStart
(Single Phase Only)
Rated
Voltage
220-240/50/1 198/264 17.5 11.2 60.0 24.0 1.5 4.5 17.2 20.0 30
380-420/50/3 342/462 6.5 4.2 28.0 16.8 - - 4.2 5.3 6
220-240/50/1 198/264 27.0 17.3 97.0 34.0 1.5 4.5 23.3 27.6 40
380-420/50/3 342/462 10.0 6.4 45.0 27.0 - - 6.4 8.0 10
220-240/50/1 198/264 31.5 20.2 126.0 44.0 1.5 4.5 26.2 31.2 50
380-420/50/3 342/462 12.1 7.8 51.5 31.0 - - 7.8 9.8 15
220-240/50/1 198/264 45.0 29.0 130.0 46.0 1.5 4.5 35.0 42.3 70
380-420/50/3 342/462 19.0 12.2 87.0 52.0 - - 12.2 15.3 25
®
Voltage
Min/Max
MCC RLA LRA LRA*
Compressor
Load
Pump
FLA
Source
Pump
FLA
Total
Unit
FLA
Terminal Board
Terminal Power Strip
Min
Circ
Amp
Max
Fuse/
HACR
1/15/15
Power Block
(IntelliStart Only)
Compressor Contactor
Run Capacitor
(Single Phase Only)
Ground Lug
Transformer
Load Pump Relay
Power Block
Reversing Valve Relay
(Reversible Units Only)
Source Pump Relay
16
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