Voltaire HTC Series User manual

www.voltairesys.com
Phone: [phone]
2900 W. Orange Ave. Ste. 100
Apopka, FL 32703
VoltAire Systems, LLC VoltAire Doc. # BA0117F
Published April 30, 2020
INSTALLATION, OPERATION, AND MAINTENANCE MANUAL FOR
HTC SERIES HEAT EXCHANGERS
Air-to-Air Counter Flow
Heat Exchangers with Capacity of
15W/ºF (27W/ºC), 20W/ºF (36W/ºC), 25W/ºF (45W/ºC),
42W/ºF (75W/ºC) and 90W/ºF (162W/ºC)
48VDC MODELS
UL 1995 and Type 4/4X

HTC Series
Installation, Operation and
Maintenance Manual
VoltAire Systems, LLC
Specifications are subject to change without notice
Page 2 of 21
VoltAire Doc. # BA0117F
Published April 30, 2020
TABLE OF CONTENTS
1. Important Information to Review Prior to Installation, Operation, and Maintenance....................................... Page 3
2. Parts Shipped Loose and Tools Required ..................................................................................................... Page 4
3. Product Description ....................................................................................................................................... Page 5
4. General Product Data .................................................................................................................................... Page 7
5. Installation Instructions .................................................................................................................................. Page 9
6. 48VDC Wiring, Startup and Controls Operation........................................................................................... Page 11
7. Cutout Drawings ......................................................................................................................................... Page 13
8. Electrical Wiring Diagrams........................................................................................................................... Page 16
9. 48VDC Control Board Trouble Shooting...................................................................................................... Page 17
10. Recommended Maintenance ....................................................................................................................... Page 18
11. Spare Parts................................................................................................................................................. Page 19
12. Warranty..................................................................................................................................................... Page 20

HTC Series
Installation, Operation and
Maintenance Manual
VoltAire Systems, LLC
Specifications are subject to change without notice
Page 3 of 21
VoltAire Doc. # BA0117F
Published April 30, 2020
1.IMPORTANT INFORMATION TO REVIEW PRIOR TO INSTALLATION, OPERATION
AND MAINTENANCE
•Read the ENTIRE MANUAL prior to installing and maintaining the heat exchanger. Do not install or
perform maintenance on the heat exchanger if you do not understand all of the instructions. Contact
VoltAire at [phone] with any technical questions or concerns.
•Warning: Improper installation and operation may cause property damage, personal injury or loss of
life. The heat exchanger should only be installed and maintained by a qualified professional in strict
accordance with the requirements within this manual and in accordance with all local, state and federal codes.
•In the event of a conflict, code requirements shall take precedence over the instructions provided within this
manual. The installer should be aware of all code requirements and should fully comply.
•Use care when transporting and lifting the heat exchanger.
•Remove power from the unit during maintenance and installation, as line voltage may be dangerous,
hazardous and lethal.
•Warning: Wear proper personal protection equipment, including but not limited to safety glasses,
goggles and gloves. Edges may be sharp.
•A field provided time delay fuse or breaker must be provided with the power supply circuit serving the heat
exchanger.The installer shall size this fuse or breaker in accordance with all applicable codes. Verify wire
terminals and voltage prior to plugging into the heat exchanger, otherwise you may damage the heat
exchanger's electrical components.
•For 48V DC power supply, verify polarity and apply correctly as improper operating voltage may result in
unit damage.
•These instructions should be retained by the owner and/or with the unit.

HTC Series
Installation, Operation and
Maintenance Manual
VoltAire Systems, LLC
Specifications are subject to change without notice
Page 4 of 21
VoltAire Doc. # BA0117F
Published April 30, 2020
2.PARTS SHIPPED LOOSE AND TOOLS/MATERIALS PROVIDED BY THE INSTALLER
Materials Shipped Loose with the Heat Exchanger
a) Gasket kit
UNIT
PART NUMBER
HTC015*
HTC020*
HTC025*
A6F0002LAA
HTC042*
A6F0007VAA
HTC090*
A6F0005VAA
b) Two (2) M6X25 Threaded Stud with two (2) M6 Nuts and two (2) M6 Lock Washers
c) M6x25 Mounting Bolts
UNIT
QUANTITY
HTC015*
HTC020*
HTC025*
8
HTC042*
8
HTC090*
13
d) ADDITIONAL SHIPPED LOOSE ITEMS
UNIT
DESCRIPTION
48 VDC Models 60" Long Wire Lead with Male Molex Plug
Required Tools and Materials provided by Installer
a) Fuse or Breaker
b) Exterior rated silicone sealant
c) M4 Torx tamper resistant screw driver
d) M6 HEX head screw driver
e) M6 Nut Driver/wrench
f) Torque wrench

HTC Series
Installation, Operation and
Maintenance Manual
VoltAire Systems, LLC
Specifications are subject to change without notice
Page 5 of 21
VoltAire Doc. # BA0117F
Published April 30, 2020
3.PRODUCT DESCRIPTION
VoltAire Systems HTC Series Counter Flow Heat Exchangers are designed for high efficiency and high
performance heat transfer in a closed airflow loop to prevent introduction of exterior air into the
equipment/cabinet. The heat exchangers are an industrial heat management system especially designed for
heat management of electronic enclosures or equipment, including those requiring battery backup. This product
is a passive thermal management system without a refrigeration system and is designed for applications where
the interior temperature may exceed the exterior (ambient) temperature. This product will work in extreme
temperature range from -40ºF to 158ºF (-40ºC to 70ºC).
Figure 1 shows the exterior and interior airflow intake and exhaust locations. Exterior air enters the heat
exchanger through the bottom / front of the unit and exhausts through the front. Interior air enters the intake
through the rear top vents and discharges through the vents below it.
Figure 1 – Heat Exchanger Airflow
The heat exchangers are UL/cUL Recognized per UL 1995/CSA 22.2 NO. 236-15 and UL tested and UL
Recognized for compliance with UL Type 4/4X. HTC Series fans are salt fog certified by a 3rd party per GR-
487-CORE 3.34.1 and ASTM B117 for 720 hours. The aluminum heat exchanger core is coated with epoxy for
additional durability in corrosive atmospheres.
An integrated 48VDC control board is used to control fan speed to optimize energy performance while
minimizing noise. The board is programmed to operate the interior fan based upon the interior temperature
within the cabinet, equipment or building. The interior fan will operate at 25% capacity continuously when the
cabinet isabove 32ºF (0ºC) and below 77ºF (25ºC). At 77ºF (25°C) the interior fan will modulate from 25% to

HTC Series
Installation, Operation and
Maintenance Manual
VoltAire Systems, LLC
Specifications are subject to change without notice
Page 6 of 21
VoltAire Doc. # BA0117F
Published April 30, 2020
100% between 77ºF (25ºC)and 104ºF (40°C). Exterior fan speed control varies based on model. Reference
Figure 10 on page 12 for fan speed design based upon interior temperature.
The 48VDC board includes a general alarm for loss of fan or high temperature (45°C),with Form C dry
contacts withNO or NCalarm output. The 48VDC board is accessible by removing the cover and front panel
on HTC015 to HTC055units as seen in Figure 4. On theHTC090unit, the control board is accessible through
the back interior fan access panel as seen in Figure 5. The 48VDC board includes a test button to verify
operation, as described in Section 6.
The heat exchanger cabinet and internal brackets arefabricated out of acrylume for improved durability. A
powder coated cover isattached with security screws to protect the unit from tampering. The unitiseasily
mounted to a cabinet or equipment with the included field installed gasket and M6 mounting kit. All operable
parts areaccessible through access panels. All units with the exception of the HTC090 are serviceable from the
exterior of the cabinet. The HTC090 is serviced from within the cabinet through the supply and return cutouts.

HTC Series
Installation, Operation and
Maintenance Manual
VoltAire Systems, LLC
Specifications are subject to change without notice
Page 7 of 21
VoltAire Doc. # BA0117F
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4.GENERAL PRODUCT DATA
Figure 2 - Model Nomenclature
Figure 3 - Unit Dimensions
MODEL
NUMBER
NOMINAL
CAPACITY1RATED VOLTAGE FULL LOAD (AMPS) 2 WEIGHT (lbs.)
NOMINAL SIZE
W x H x D (in.)
HTC015B 15 W/ºF (27 W/ºC) 48 VDC 0.5
22 12.3 x 20.0 x 7.6
HTC020B 20 W/ºF (36 W/ºC) 48 VDC 0.8
HTC025B 25 W/ºF (45 W/ºC) 48 VDC 1.7
HTC042B 42 W/ºF (75 W/ºC) 48 VDC 4.3 37 18.0 x 24.0 x 8.0
HTC090B 90 W/ºF (162 W/ºC) 48 VDC 4.8 86 19.4 x 46.3 x 11.3
1
Capacity is nominal based upon free airflow without restrictions; Locating the heat exchanger where airflow is restricted may reduce capacity;
Nominal capacity is at exterior temperature of 113ºF (45ºC) and interior temperature of 131ºF (55ºC), Δ18ºF (Δ10ºC)
2Field provided fuse or breaker is required; Installer shall verify size and insure compliance with all applicable codes.

HTC Series
Installation, Operation and
Maintenance Manual
VoltAire Systems, LLC
Specifications are subject to change without notice
Page 8 of 21
VoltAire Doc. # BA0117F
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Figure 4 – HTC 015-042 Configuration
Figure 5 – HTC 090 Series Configuration

HTC Series
Installation, Operation and
Maintenance Manual
VoltAire Systems, LLC
Specifications are subject to change without notice
Page 9 of 21
VoltAire Doc. # BA0117F
Published April 30, 2020
5. INSTALLATION INSTRUCTIONS
The heat exchanger can be installed on any flat vertical surface.Do not install the unit in a horizontal position
and verify the unit is level.The heat exchanger should be located on a cabinet or equipment such that airflow
is not restricted by obstructions of the interior or exterior intake and exhaust openings.Obstruction of airflow
will reduce capacity of the heat exchanger. Figure 6 illustrates a typical installation.
Using the corresponding cutout template shown in Section 7 prepare the wall for the interior intake and exhaust
openings and fastener locations. Clean the mounting surface to remove any dust, grease and/or debris,
including any metal burrs resulting from metal cutting.
Figure 6 - Typical Installation
Remove the cover from the heat exchanger by removing the M4 Torx security screws on the sides of the cover.
Set the cover to the side as it will not be placed back on the unit until installation is complete.
Using the gasket kit provided, place the gasket on the back of the heat exchanger immediately abutting the
mounting-hole locations. Figure 7 is a general view that reflects the location of the gasket with the hatched
area. Three different lengths of gasket are found in the gasket kit that accompanies the unit. The two longest
strips are used on the sides, the shortest length is used on the bottom and midsection (between the supply and
return openings), and the remaining strip runs across the entire length of the top of the unit. Install the strip that
runs along the top first, then the two sides strips, and finally the middle and bottom strip. Ensure there are no
gaps in the gasket and verify the entire perimeter is sealed with gasket.

HTC Series
Installation, Operation and
Maintenance Manual
VoltAire Systems, LLC
Specifications are subject to change without notice
Page 10 of 21
VoltAire Doc. # BA0117F
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Insert two (2) M6x25 threaded studs provided into the top left and right corner mounting holes on the back of the
unit. These studs are provided to allow the unit to be placed on the cabinet in a temporary manner while the
other fasteners are installed. Do not over-tighten these studs as they will be tightened fully when the nuts are
installed. Install the M6x25 bolts and washer at each of the mounting locations. Install the M6 nuts and washers
on the M6 studs. Tighten the M6 mounting bolts and nuts on the M6 studs to 50 in-lbs torque.
From the exterior, inspect the gasket to verify the gasket is tight and there are no visible leakage points. Using
a field supplied sealant, seal around top, bottom and sides of the heat exchanger against the cabinet. Note that
the heat exchanger is fully maintainable without removal from the cabinet/equipment, therefore this sealant will
not be required to be removed for the purpose of routine maintenance. Therefore use a liberal amount of
sealant. Once the sealant is sufficiently dry, place the heat exchanger cover on the heat exchanger and fasten
with the security screws.
Installation of the heat exchanger is complete, with the exception of applying power and starting the unit per the
instructions below.
Figure 7 – Rear/Back of Counter Flow Heat Exchanger

HTC Series
Installation, Operation and
Maintenance Manual
VoltAire Systems, LLC
Specifications are subject to change without notice
Page 11 of 21
VoltAire Doc. # BA0117F
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6.48 VDC MODEL WIRING, START-UP AND CONTROLS INSTRUCTIONS
STOP AND READ BEFORE PROCEEDING! Proceed with CAUTION as the 48VDC must be wired with the
proper polarity. Failure to connect the 48VDC power cable correctly may damage the heat exchanger control
board and/or motors. Verify supply voltage is nominal 48VDC, with no more than 20% voltage variation. The
connection to the heat exchanger shall be made with a male connection with the pin numbers and wire
locations as shown in Figure 8. A 48" long lead with male molex connector is shipped loose for connection to
the power source. A time delay fuse or breaker is required and shall be sized per applicable code.
Ensure that the heat exchanger is fully assembled and verify that the fans are protected with the provided
covers. Any loose parts/tools shall be removed and be careful to avoid body contact with the moving fans.
The 48VDC internal power cable is to be installed by the installer. The internal power/alarm wire with molex
plug is shipped within the lower air flow cutout. The installer is to place the molex into the cutout on the rear of
the unit, as shown in Figure 7. Insert the molex plug into the opening snapping it into place.
Apply power to the unit: the unit may not automatically operate if temperatures are not within the range as
shown on Figure 10. The control board, as shown in Figure 9, is designed for simple operation. The board
includes a test button, which will operate the fans at maximum 100% capacity for a period of 2 minutes and 30
seconds. Upon startup, press and hold the button for 2 seconds and the unit will begin test mode. The test
mode will continue until the test period ends, or the test mode button is pushed again for 2 seconds.
Figure 8 – 48 VDC Wire Connections

HTC Series
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VoltAire Systems, LLC
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Page 12 of 21
VoltAire Doc. # BA0117F
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The alarm output is a Form C contact closure which is rated at 2A at 30VDC. Form C is essentially a SPDT
switch without data transmission. NO (Normally Open) and NC (Normally Closed) contacts are provided for
alarm output. Upon an active alarm the contact will close if NC pins are used or open if NO pins are used. An
alarm state will be triggered by a temperature alarm at 45ºC, a fan failure, and/or thermistor failure.
FIGURE 9 – CONTROL BOARD DRY CONTACT NO/NC ALARM
Figure 10 - Fan Speed/Interior Temperature Graph

HTC Series
Installation, Operation and
Maintenance Manual
VoltAire Systems, LLC
Specifications are subject to change without notice
Page 13 of 21
VoltAire Doc. # BA0117F
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7.CABINET/EQUIPMENT CUTOUT DRAWINGS
The mounting/cutout drawings below reflect the interior airflow intake and exhaust cutouts as well as the
mounting-hole spacing/size for the M6 mounting studs and bolts.
Figure 11 – HTC015, HTC020 and HTC025 Mounting Template

HTC Series
Installation, Operation and
Maintenance Manual
VoltAire Systems, LLC
Specifications are subject to change without notice
Page 14 of 21
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Figure 12 – HTC042 Mounting Template

HTC Series
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Maintenance Manual
VoltAire Systems, LLC
Specifications are subject to change without notice
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Figure 13 – HTC090 Mounting Template

HTC Series
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VoltAire Systems, LLC
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VoltAire Doc. # BA0117F
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8. ELECTRICAL WIRING DIAGRAMS
Figure 14 – 48VDC Wiring Diagram for all
48VDC Models with a Speed Control Board

HTC Series
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VoltAire Systems, LLC
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VoltAire Doc. # BA0117F
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9. 48VDC CONTROL BOARD OPERATION AND TROUBLESHOOTING
The Voltaire Systems DC control board has an alarm function that activates a Form C contact closure alarm
under the following circumstances. The board is designed with both a Normally Open and Normally Closed
contact option. This is selected based on the pin usage on the board. Upon alarm, the contacts will close if
Normally Open is selected or will open if Normally Closed is selected. Note that these alarms are capable of
being present during test mode.
•An internal temperature exceeding 45°C will result in an alarm. The board will go into an alarm state but
continue to command the fans to operate at 100% speed. A high temperature alarm may be the result of a
bad fan motor, defective thermistor, board failure or inadequate heat exchanger size for the heat load.
•The loss of thermistor input will result in an alarm. If the thermistor is defective or disconnected, the control
board will go into an alarm state but continue to command the fans to operate at 100% speed. To access
the thermistor, remove the cover and the front panel, and the thermistor is located in the upper left hand
chamber of the interior airflow path (rear of unit). First check that the thermistor is properly installed and
plugged into the board. If detached, plug the thermistor into the board at the THRM1 board terminal,
reassemble the unit with front panel and cover, and retest. The NTC thermistor is 10,000 ohms at @ 25°C
and uses the J Temperature-Resistance curve. If the thermistor is not functioning properly and has failed,
remove the power from the Heat Exchanger model and replace the thermistor and re-test.
•A loss of fan will result in an alarm. The board will go into an alarm state but continue to command the fans
to operate at 100% speed. Determine which fan is not running and operating properly by using the test
button, remove power to the unit, check all wire connections to ensure you have good connections to the
defective fan. If you find that there are no connection problems replace the fan. Once you have a
replacement fan remove the cosmetic cover and the front cover to expose the fans, replace the defective
fan, reconnect the wires, replace the front panel and cover and apply power to the unit and retest.
•A loss of power to the board will result in an alarm state.

HTC Series
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Page 18 of 21
VoltAire Doc. # BA0117F
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10. RECOMMENDED MAINTENANCE
Although the heat exchangers are designed to require minimal maintenance, it is recommended that the units
be inspected periodically for proper operation. The following items can be reviewed during other routine
maintenance of the cabinet/equipment:
•In order to verify the operation of the interior and external fans, use the control board test button to verify
operation of the interior and exterior fans.
•Verify that the unit is sealed properly. The field sealing of the unit to the cabinet/equipment should be
inspected to ensure proper sealing (See Section 5).
•The heat exchanger core includes two flow paths, an interior and exterior. These flow paths may be
vacuumed to remove any dust and dirt. To do so, remove the supply voltage to the unit to ensure that the
fans are not operating.
oFor HTC015/HTC020/HTC025, remove the heat exchanger cover by removing the Torx security
screws on the left and right side. Remove the front panel to gain access to both the interior and
exterior flow paths and vacuum both sides. Replace the front panel, verify proper sealing, and
replace the cover.
oFor HTC042, remove the heat exchanger cover by removing the Torx security screws on the left
and right side. Use the front access panel to gain access to the interior fan, control board, and
interior flow path. Use the removable bottom bracket to gain access to the exterior fan and exterior
flow path. Vacuum both flow paths and sides. Replace access panel and bracket, verify sealing,
and replace cosmetic cover.
oFor HTC090, remove the heat exchanger cover by removing the Torx security screws on the left
and right side. Use the access panels on the interior side to gain access to both the interior and
exterior airflow path and vacuum both sides. Replace the access panels, verify proper sealing, and
replace the cover

HTC Series
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Maintenance Manual
VoltAire Systems, LLC
Specifications are subject to change without notice
Page 19 of 21
VoltAire Doc. # BA0117F
Published April 30, 2020
11. SPARE PARTS
HEAT EXCHANGER MODEL NUMBER(S) PART NUMBER PART DESCRIPTION
HTC015B A4Z0003VA*
48VDC 15W
Controller 0-12VDC Control
HTC020B A4Z0004VA* 48VDC 20W
Controller 0-12VDC Control
HTC025B A4Z0005VA* 48VDC 25W
Controller 0-12VDC Control
HTC042B
HTC090B A40001VA* 48VDC 42W - 90W
Controller 0-12VDC Control
HTC***B
(All Capacities) Y4S0001ARA Thermistor
HTC015B, HTC020B, HTC025B C3S0007EAA Interior and Exterior
Fans
HTC042B C3S0008SAA Interior and Exterior
Fans
HTC090B C3S0006EAA Interior and Exterior
Fans

HTC Series
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Page 20 of 21
VoltAire Doc. # BA0117F
Published April 30, 2020
12. WARRANTY
VOLTAIRE SYSTEMS THERMAL UNITS NON-TRANSFERABLE
STANDARD LIMITED WARRANTY, DISCLAIMERS, AND LIMITATIONS OF
LIABILITY
(Applies to All Heat Exchangers, Pressurization Units,
Fan Units, and Air Conditioners)
The VoltAire Systems, LLC ("VoltAire") Non-Transferable Limited Warranty (“Limited Warranty”) is applicable for 12 months following
the shipment of the product to the original purchaser ("Purchaser") defined as the "Warranty Period". VoltAire warrants to the original
purchaser during the Warranty Period that all materials and workmanship are free of defects of quality and operation that would impair
the usefulness of the original air conditioner, fan unit, pressurization unit or heat exchanger (collectively herein referred to as
"Product") during the Warranty Period. This Limited Warranty is for all components of the Product, except filters, when installed and
operated under the following conditions:
A. In strict accordance with the Product's Installation and Operation Manual, as may be revised from time to time with the
latest version available at www.voltairesys.com.
B. Maximum voltage variation no greater than plus or minus 10% of nameplate nominal rating.
C. Maximum frequency variation no greater than plus or minus 3 Hz. of nameplate nominal rating.
D. Must not exceed minimum and maximum stated temperatures on the nameplate.
E. Not to exceed (BTU/Hr.) rating, including any heat sink, as indicated on the nameplate.
F. Installed per all local, State and Federal legal requirements.
G. The unit must not be restarted for a period of five (5) minutes after intentional or accidental shut-off of a compressor.
(This does not apply to heat exchanger or filter fan.)
The Limited Warranty is void and not applicable if:
A. The Product is installed improperly
B. The Product is not maintained properly, including prolonged operation with dirty filters or coils
C. The Product is modified, abused and/or tampered
D. The Product is applied in an incorrect manner, including operation within a corrosive atmosphere (including but not
limited to coastal applications)
E. The Product is used with the incorrect refrigerant (air conditioners)
F. The Product is damaged and/or inoperable due to accidents or events beyond the reasonable control of VoltAire and
Acts of God
G. The Product is repaired with parts not provided by VoltAire
H. The Product is installed and operated outside the United States, Mexico, and/or Canada.
Damage during freight is not included with this Limited Warranty. The Purchaser must insure the Product is installed by a competent,
professional, qualified contractor, following all local, state, and national legal requirements and industry standards. The Purchaser
must provide adequate maintenance (e.g. filter changes, coil cleanings).
The Limited Warranty covers the Product for the Purchaser only during the Warranty Period, and the Limited Warranty does not
include any labor, freight, and/or consequential damages or loss. Upon Notification by the Purchaser, VoltAire solely reserves the
right to either, as Purchaser’s sole remedy:
•Ship replacement parts to the Purchaser for the Purchaser's infield replacement of the part. Infield replacement will require the
Purchaser to provide a purchase order to VoltAire for the standard cost of the part and after infield replacement return the
original part to VoltAire with freight cost by Purchaser. Within fourteen (14) days of receipt of the returned part VoltAire will