Greenheck Fan PVE-20, PVE-45, PVE-35 User Manual
Part #472846
®
Heat Recovery Ventilators
Installation, Operation and Maintenance Manual
Please read and save these instructions. Read carefully before attempting to assemble, install, operate or maintain the
product described. Protect yourself and others by observing all safety information. Failure to comply with instructions
could result in personal injury and/or property damage! Retain instructions for future reference.
Models: PVe-20
PVe-35
PVe-45
PVe-55
General Safety Information
Only qualified personnel should install this system.
Personnel should have a clear understanding of these
instructions and should be aware of general safety
precautions. Improper installation can result in electric
shock, possible injury due to coming in contact with
moving parts, as well as other potential hazards.
Other considerations may be required if high winds
or seismic activity are present. If more information
is needed, contact a licensed professional engineer
before moving forward.
DANGER
Always disconnect power before working on or near
this equipment. Lock and tag the disconnect switch
or breaker to prevent accidental power up.
CAUTION
When servicing the unit, the internal components
may be hot enough to cause pain or injury. Allow
time for cooling before servicing.
CAUTION
Precaution should be taken in explosive
atmospheres.
1. Follow all local electrical and safety codes, as well
as the National Electrical Code (NEC), the National
Fire Protection Agency (NFPA), where applicable.
Follow the Canadian Electric Code (CEC) in
Canada.
2. All moving parts must be free to rotate without
striking or rubbing any stationary objects.
3. Unit must be securely and adequately grounded.
4. Do not spin fan wheel faster than maximum
cataloged fan RPM. Adjustments to fan speed
significantly affects motor load. If the fan RPM is
changed, the motor current should be checked to
make sure it is not exceeding the motor nameplate
amps.
5. Do not allow the power cable to kink or come in
contact with oil, grease, hot surfaces or chemicals.
Replace cord immediately if damaged.
6. Verify that the power source is compatible with the
equipment.
7. Never open access doors to the unit while it is
running.
Model PVe Heat Recovery Unit
1
Receiving
Upon receiving the product, check to make sure
all items are accounted for by referencing the bill
of lading to ensure all items were received. Inspect
each crate for shipping damage before accepting
delivery. Notify the carrier if any damage is noticed.
The carrier will make notification on the delivery
receipt acknowledging any damage to the product.
All damage should be noted on all the copies of
the bill of lading which is countersigned by the
delivering carrier. A Carrier Inspection Report should
be filled out by the carrier upon arrival and the Traffic
Department. If damaged upon arrival, file claim
with carrier. Any physical damage to the unit after
acceptance is not the responsibility of Greenheck Fan
Corporation.
Unpacking
Verify that all required parts and the correct quantity
of each item have been received. If any items are
missing, report shortages to your local representative
to arrange for obtaining missing parts. Sometimes it
is not possible that all items for the unit be shipped
together due to availability of transportation and truck
space. Confirmation of shipment(s) must be limited to
only items on the bill of lading.
Machined parts coated with rust preventive should
be restored to good condition promptly if signs of
rust occur. Immediately remove the original rust
preventive coating with petroleum solvent and clean
with lint-free cloths. Polish any remaining rust from
surface with crocus cloth or fine emery paper and oil.
Do not destroy the continuity of the surfaces. Wipe
clean thoroughly with Tectyl® 506 (Ashland Inc.) or
the equivalent. For hard to reach internal surfaces or
for occasional use, consider using Tectyl® 511M Rust
Preventive or WD-40® or the equivalent.
Handling
Units are to be rigged and moved by the provided
lifting points or fork lifting points (see page 4). Handle
each piece in such a way as to keep from scratching
or chipping the coating. Damaged finish may reduce
ability of the unit to resist corrosion.
Storage
Units are protected against damage during shipment.
If the unit cannot be installed and operated
immediately, precautions need to be taken to prevent
deterioration of the unit during storage. The user
assumes responsibility of the unit and accessories
while in storage. The manufacturer will not be
responsible for damage during storage. These
suggestions are provided solely as a convenience to
the user.
Inspection and Maintenance during
Storage
While in storage, inspect units once per month. Keep
a record of inspection and maintenance performed
If moisture or dirt accumulations are found on parts,
the source should be located and eliminated. At each
inspection, rotate all moving components by hand
ten to fifteen revolutions to distribute lubricant on
motor and bearings. If paint deterioration begins,
consideration should be given to touch-up or
repainting. Units with special coatings may require
special techniques for touch-up or repair.
Model PVe Heat Recovery Unit
2
Table of Contents
Plate
Heat
Exchanger
EXHAUST AIR
Exhaust
Fan
OUTDOOR
AIR
Basic Operation
Basic Operation . . . . . . . . . . . . . . 3
Installation
Supplemental Installation, Operation and
Maintenance Manuals . . . . . . . . . . . 3
Installation . . . . . . . . . . . . . . . . 3
Installation Stages . . . . . . . . . . . . . 4
Lifting with a Crane or Forklift . . . . . . . . 4
Roof Curb and Rail Mounting
Recommended Roof Opening . . . . . . . . 4
Service Clearances . . . . . . . . . . . . 5
Roof Curb Mounting . . . . . . . . . . . . 6
Curb Dimensions and Weights . . . . . . . . 6
Ductwork Connections . . . . . . . . . . . 6
Rail Mounting / Layout . . . . . . . . . . . 7
Access Panel Description and Location . . . 7
Dimensional Data . . . . . . . . . . . . . 8
Drain Trap . . . . . . . . . . . . . . . 8
Electrical Information
General Electrical Information . . . . . . . . 9
Control Center Components . . . . . . . . . 10
Electric Heater Application/Operation . . . . . 10
Optional Accessories
Frost Control Application/Operation . . . . . 11
Economizer Application/Operation . . . . . . 11
Variable Frequency Drives and Wiring . . . . 12-13
Typical Wiring Diagram . . . . . . . . . . . 14
Sensors and Lights . . . . . . . . . . . . 15
Remote Control Panel and Wiring . . . . . . 16
Sensors Mounted by Factory . . . . . . . . 17
Sequence of Operation
Start-Up
General Start-Up Information . . . . . . . . 18
Optional Accessories . . . . . . . . . . . 19
Unit Start-Up, Fans . . . . . . . . . . 20-21
Routine Maintenance Checklist
Overview. . . . . . . . . . . . . . . . . 22
General . . . . . . . . . . . . . . . . . 23
Fan Belts. . . . . . . . . . . . . . . . . 23
Fan Motors . . . . . . . . . . . . . . . . 23
Fan Wheel and Fasteners . . . . . . . . . . 24
Fan Bearings . . . . . . . . . . . . . . . 24
Filters . . . . . . . . . . . . . . . . . . 24
Door Seal Maintenance . . . . . . . . . . . 24
Parts List . . . . . . . . . . . . . . . . . 25
Sequence of Operation . . . . . . . . . . . 25
Troubleshooting – Airflow . . . . . . . . . . 26
Troubleshooting – Unit . . . . . . . . . .27-28
Maintenance Log . . . . . . . . . . . 29-31
Warranty . . . . . . . . . . . . . Backcover
The PVe brings in fresh outdoor air and removes stale
exhaust air from the building. Prior to discharging
the exhaust air, the plate heat exchanger transfers
energy from the exhaust air to the incoming outdoor
air. When used in the cooling mode, heat energy is
transferred from incoming outdoor air to the exhaust
air. Simply put, this unit preconditions the outdoor air
to save money on heating and cooling costs.
SIDE VIEW
RETURN DUCT
SUPPLY DUCT
Supplemental Installation,
Operation and Maintenance
Manuals
Refer to the following Installation, Operation and
Maintenance Manuals for additional details:
Part #462844 — Exhaust Weatherhood
Additional manuals are available for each accessory
used in the PVe. These additional manuals are
provided by the respective manufacturers and are
included with unit shipment.
Installation
The system design and installation should follow
accepted industry practice, such as described in the
ASHRAE Handbook.
Adequate space should be left around the unit for
filter replacement and maintenance. Sufficient space
should be provided on the side of the unit for routine
service and component removal should that become
necessary.
See Service Clearances and Access Panel Description
sections for more details.
WARNING
All factory provided hoisting and fork lifting points
must be used when lifting the unit. When rigging for
hoisting with a crane, spreader bars must be used.
Failure to comply with this safety precaution could
result in property damage, serious injury or death.
See Installation Stages for additional details.
Model PVe Heat Recovery Unit
3
Installation Stages
Once the PVe Heat Recovery Ventilator is delivered
to the jobsite, the actual installation occurs in several
distinct stages.
1. Installation location must be carefully considered.
Service clearances needed for later maintenance
of the unit must be taken into consideration,
access to Return Air and Discharge Air ducting
must be anticipated. And structural support
of the unit must be taken into consideration.
See appropriate sections of this manual for
further information. If electric wiring is going
to be brought into the cabinet from beneath
(recommended), preparations for that step must
be taken during the planning stage. If possible, a
GKD curb should be installed prior to installation
of roofing materials so that flashing can be run up
the sides of the curb.
2. Hoisting the cabinet can be accomplished with
either a crane or a fork lift. If a forklift is used, the
forks must extend all the way through the cabinet
and project from the far side. The forks should
be padded with a layer of ¼-inch thick plywood
or other suitable material. If a forklift is used, the
cabinet cannot be lowered directly onto the GKD
curb unit because the forks will be in the way. It
will be necessary to set the unit onto appropriate
dunnage for final lowering after the forks are
removed.
If a crane is used, hoisting points are provided at
each corner of the cabinet. Small, padded hooks
must be inserted into the hoisting points. There
is very little internal clearance inside the cabinet
base and the use of large lifting hooks will either
dig into the cabinet structure or else interfere with
the seating of the cabinet on the GKD curb.
2. Physical installation of the unit should be
completed prior to installation of electrical wiring.
Condensate drains should be connected and if
necessary, heat strips installed on the drains to
prevent freezing of the traps. A final check should
be made to ensure that the unit has been installed
level by using the bottom of the cabinet as a
reference, not the top (the cabinet roof is sloped
to the rear). Ensure that all ductwork has been
properly and permanently assembled.
3. Prior to wiring the unit, installer should verify that
all optional accessories are accounted for. Verify
that electric components such as motors are rated
properly for the voltage actually being used. Note
that some of the illustrations and pictures used in
this manual show the use of three phase power
and if the user actually has single phase power,
there will be minor variations present. The unit
should be wired according to the supplied wiring
diagrams and Best Practices. Careful testing
and balancing of the power source should be
accomplished at this time.
Model PVe Heat Recovery Unit
4
Lifting
Forklift lifting
points
Crane hoisting points
(typical)
Lifting with a Crane
1. Before lifting, be sure that all shipping material
has been removed from unit.
2. To assist in determining rigging requirements,
weights are shown below.
3. Unit must be lifted by simultaneously hoisting
at all four corner lifting points provided on base
structure, ensuring proper load distribution and
support at each corner.
4. Rigger to use suitable mating hardware to attach
to unit corner lifting points.
5. Spreader bar(s) must
span the unit to
prevent damage to
the cabinet by the lift
cables.
6. Always test-lift the
unit to check for
proper balance
and rigging before
hoisting to desired
location.
7. Never lift units by weatherhoods.
8. Never lift units in windy conditions.
9. Preparation of curb and roof openings should be
completed prior to lifting the unit and setting on
the curb.
The weights shown are a
worst case scenario based
on the sheet metal and
component weights for
the unit. These weights
include sheet metal weights
added together with the
largest motors, blowers and
accessories for the units.
Unit Weights (lbs.)
Model
PVe-20 1300
PVe-35 1600
PVe-45 2100
PVe-55 2700
Approx.
Weight
Lifting with a Forklift
Unit base rail includes forklift lifting locations. Use
weights shown to determine forklift size requirements.
Roof Curb and Rail Mounting
CLEARANCE
B
C
A
D
When installed on a roof, a typical installation
will include at least one roof penetration in order
to deliver return air to the unit from the space.
Additionally, a second roof penetration may be used
for supply air discharge to the space.
Service Clearances
C
B
CLEARANCE
Intake and Discharge Options
Option Bottom Top Side End
OA Intake X
SA Discharge X X
RA Intake X
EA Discharge X
OA - Outdoor Air
SA - Supply Air (to the space)
RA - Return Air (from the space)
EA - Exhaust Air
SA Discharge
OA Intake
CLEARANCE
D
D
B
A
C
EA Discharge
SA Discharge
D
Model A B C D
PVe-20
PVe-35
PVe-45
PVe-55
All dimensions are shown in inches (millimeters). The
weatherhoods include 2-inch aluminum mesh filters that
are removed out of the end of the hood as shown in this
drawing and require extra clearance for removal.
36
(920)
48
(1220)
60
(1530)
72
(1830)
36
(920)
36
(920)
36
(920)
36
(920)
A
36
(920)
36
(920)
36
(920)
36
(920)
60
(1530)
60
(1530)
60
(1530)
60
(1530)
E
RA Intake
F
Duct Dimensions
Model A B C D E F
PVe-20
PVe-35
PVe-45
PVe-55
All dimensions are shown in inches (millimeters).
10.7
(280)
11.9
(310)
14.1
(360)
16.4
(420)
Position the unit roof opening such that the Return Air
Intake will line up with the corresponding ductwork.
If applicable, adjust position to also accommodate
the SA Discharge vent. Make certain that proposed
positioning of the unit still maintains recommended
service clearances.
12.2
(310)
13.7
(350)
16.0
(410)
19.2
(490)
10.3
(270)
11.4
(290)
13.3
(340)
15.9
(450)
11.8
(300)
13.1
(340)
14.5
(370)
18.6
(480)
22.0
(570)
34.0
(870)
46.0
(1170)
60.0
(1530)
14.0
(360)
14.0
(360)
14.0
(360)
14.0
(360)
Do not face the Outdoor Air Intake of the unit into
prevailing wind and also keep the air intake away
from any other exhaust fans. Likewise, position the
Exhaust Air Discharge opening away from any other
outdoor air intakes of other equipment.
When cutting duct openings, cut opening one inch
larger (25 mm) than duct size to allow clearance for
installation. Area enclosed by roof curb must comply
with clearance to combustible materials. If the roof
is constructed of combustible materials, area within
the roof curb must be ventilated, left open or covered
with non-combustible material which has an “R” value
of at least five (5). If area within curb is left open,
higher radiated sound levels may result.
Where the supply or warm air duct passes through
a combustible roof, a clearance of one inch must be
maintained between the outside edges of the duct
and combustible material in accordance with NFPA
Standard 90A.
Model PVe Heat Recovery Unit
5
Roof Curb Mounting
R
o
t
a
t
i
o
n
R
o
t
a
t
i
o
n
R
o
t
a
t
i
o
n
POOR
GOODPOOR
Turning
Vanes
R
o
t
a
t
i
o
n
R
o
t
a
t
i
o
n
R
o
t
a
t
i
o
n
POOR
GOODPOOR
Turning
Vanes
Roof curb assembly and mounting instructions are
contained in the Roof Curb Assembly Instructions
supplied with Model GKD roof curb.
Rooftop PVe units require curbs to be mounted first,
in accordance with their appropriate instructions.
Curb unit is to be installed and then duct connections
are to be made prior to setting of the unit.
1. Factory Supplied Roof Curbs: Roof curbs are
Model GKD. The GKD ships in a knockdown kit
(which includes duct adapter) and requires field
assembly by others. Assembly instructions are
included with the GKD curbs.
2. Install Curb: Locate the assembled curb over
roof opening and verify precise location of curb
relative to the roof opening, in accordance with
dimensions given previously. Fasten curb loosely
in place and then shim as needed to ensure a
level installation. Tighten roof fastening hardware
and then re-check for level. Verify that diagonal
dimensions of installed curb are plus or minus
1/8-inch of each other.
3. Install Ductwork: Install needed ductwork in
accordance with SMACNA and AMCA guidelines.
Duct adapter is provided to support ducts prior
to setting the unit.
4. Install Insulation: One-inch deep insulation
pans are provided with the curb assembly. Set
the insulation pans per instructions and then
install insulation in the pans prior to setting
the unit. Insulation is not provided by the unit
manufacturer, it is to be supplied by others.
5. Set the PVe Unit: Lift unit to a point directly
above the curb and duct openings. Guide unit
carefully while lowering in order to align with duct
openings. The roof curb will seat in a recess in
the base of the PVe unit. Verify that the unit is
properly seated on the curb and is level.
Unit Side
1.895
Unit Base
Curb Dimensions and Weights
L
W
Unit Size L W
PVe-20 99.4 36.8 195
PVe-35 99.4 44.6 216
PVe-45 105.9 56.3 261
PVe-55 111.7 71.3 316
All dimensions are shown in inches.
Ductwork Connections
Examples of poor and good fan-toduct connections are
shown below. Airflow
out of the fan should
be directed straight or
curve the same direction
as the fan wheel rotates.
Poor duct
installation will
result in low
airflow and other
system effects.
n
o
i
t
a
t
o
R
Length of Straight Duct
GOOD
Curb Weight
(lbs.)
4.844
1.549
Curb Cap Details for Factory Supplied Roof Curbs
Model PVe Heat Recovery Unit
6
Roof Curb
0.775
Dimensions are shown in inches.
Insulation Pan
Recommended Discharge Duct Size and Length
Unit Size Blower Size Duct Size Straight Duct Length
PVe-20 9 14 x 14 36
PVe-35 10 20 x 20 36
PVe-45 12 20 x 20 36
PVe-55 15 28 x 28 60
All dimensions are shown in inches.
• Recommended duct sizes are based on velocities across the
cfm range of each model at approximately 800 feet per minute
(FPM) at minimum airflow and up to 1600 fpm at maximum
airflow. Recommended duct sizes are only intended to be a
guide and may not satisfy the requirements of the project.
Refer to plans for appropriate job specific duct size and/or
velocity limitations.
• Straight duct lengths were calculated based on 100% effective
duct length requirements as prescribed in AMCA Publication
201. Calculated values have been rounded up to nearest foot.
Rail Mounting / Layout
D
C
A B
An alternative method of unit installation is to mount
the unit on rails supplied by others. The purpose of
mounting the unit on either rails or the GKD curb is to
elevate the unit away from moisture conditions and
to provide proper clearance for installation of water
drain traps.
• Rails should be designed to handle the weight of
the PVe unit, taking into consideration weight per
square inch on bearing surfaces. Rails should be
positioned as shown in the drawing below, taking
into consideration proper load distribution and
support by roof support elements.
• Make sure that rail positioning does not interfere
with either the RA Intake duct or the optional
straight down SA Discharge duct.
• Rails should extend beyond the unit a minimum
of 12 inches.
• Set unit on rails.
Access Panel Description and
Location
5
3
2
1
Filters
1
2
Optional OA Damper
Optional RA Damper
Optional Face and Bypass Dampers
Plate Heat Exchanger
Optional Preheater
4
Isometric view of
PVe on rails
C
A B
Side view of
PVe on rails
Unit Size A
PVe-20 5 14 13.25 7.75
PVe-35 5 14 12.00 6.50
PVe-45 5 14 15.50 10.5
PVe-55 5 14 18.75 13.25
All dimensions are shown in inches.
*Zones B and C identify regions/zones where rails may
not be place due to ductwork.
B* C* D
D
3
4
5
Plate Heat Exchanger
Control Center
Blowers
Model PVe Heat Recovery Unit
7
Dimensional Data Drain Trap
Filters
Filters
Face/Bypass Damper
Plate Heat
Exchanger
Outdoor
Air Hood
B
AD
CLEARANCE
C
D
D
CLEARANCE
C
D
D
The PVe plate heat exchanger is provided with two
stainless steel drain pans and each is equipped with
a one inch MPT drain fitting. A drain trap must be
installed on each drain fitting to allow excess water
to flow out of the drain pans. More importantly,
though, due to the negative internal static pressure
inside the PVe cabinet, installing drain traps prevents
outdoor air from being pulled into the cabinet and
consequently causing overfilling of the drain pans or
misting of PVe components.
To ensure the drain trap works properly, the trap
height must account for the difference in static
pressure between ambient conditions outside the
unit and the negative static pressure inside the PVe
cabinet. An assumption of 3.0 in. wg differential is
normally sufficient for all PVe units and this would
require a trap design as shown. If the internal static is
believed to be higher, consult the factory.
Outdoor Air Hood
Outdoor
Air Hood
Bypass
Damper
Face
Filters
Damper
Filters
Face/Bypass Damper
Plate Heat
Exchanger
Top view
AD
Plate Heat
Exchanger
Exhaust
Air Hood
Control Center
E
C
B
Filters
Side view
Unit
Size
PVe-20
PVe-35
PVe-45
PVe-55
A B C D E
104.1
(2650)
104.1
(2650)
110.6
(2810)
116.5
(2959)
59.7
(1520)
59.7
(1520)
59.7
(1520)
59.7
(1520)
41.5
(1060)
49.2
(1250)
61.1
(1560)
76.1
(1940)
All dimensions are shown in inches (millimeters).
Door handles, hinges and other protrusions are not
included in the dimensions above. Dimensions are
rounded up to the nearest .1 inch (2.54 millimeters).
20.3
(520)
25.2
(640)
25.2
(640)
25.2
(640)
4 in.
Refer to local codes to determine drainage
2 in.
requirements. If draining onto a roof, place a drip pad
20.7
(530)
17.7
(450)
19.0
(490)
beneath the drain outlet to protect the roof. If draining
onto a roof is not acceptable, a drain line must be
attached to the drain trap. The drain line must be
pitched away from the unit at least 1/8-inch per foot.
On longer runs, an air break should be incorporated
to ensure proper drainage. Local codes may require
drainage into a waste water system.
Drainage problems result not only from improper
23.8
(610)
drain trap design, but also from lack of maintenance
in the PVe cabinet. Algae can form in the drain pans
and traps and cause reduced water flow, which can
in turn result in a backup in the drain system. Regular
maintenance and inspection will prevent this from
occurring. If the drains have a cleanout opening, be
sure and close the opening after cleaning and refill
the trap with water.
Model PVe Heat Recovery Unit
8
Electrical Information
The unit must be electrically grounded in accordance
with the current National Electrical Code, ANSI/
NFPA 70. In Canada, use current CSA Standard
C22.1, Canadian Electrical Code, Part 1. In addition,
the installer should be aware of and comply with
any local ordinances or electrical power company
requirements that might apply. System power wiring
must be properly fused and conform to the local and
national electrical codes. System power wiring is to
the main disconnect (door interlocking disconnect
switch standard on most units) or distribution block
and must be compatible with the ratings shown on
the nameplate: supply power voltage, phase, and
amperage (Minimum Circuit Amps - MCA, Maximum
Overcurrent Protection - MOP). All wiring beyond this
point has been done by the manufacturer and cannot
be modified without affecting the unit’s agency /
safety certification.
If field installing an additional disconnect switch, it
is recommended that there be at least four feet of
service room between the switch and system access
panels. When providing or replacing fuses in a fusible
disconnect, use dual element time delay fuses and
size according to the rating plate.
If power supply is desired through the bottom of unit,
run the wiring through the curb, cut properly aligned
holes in the insulation pan and the bottom of the PVe
cabinet bottom and wire to the disconnect switch.
Seal penetrations to prevent leakage or air infiltration.
The electric supply to the unit must meet stringent
requirements for the system to operate properly.
Voltage supply and voltage imbalance between
phases should be within the following tolerances.
If the power is not within these voltage tolerances,
contact the power company prior to operating the
system.
Voltage Supply: See voltage use range on the rating
plate. Measure and record each supply leg voltage at
all line disconnect switches. Readings must fall within
the allowable range on the rating plate.
Voltage Imbalance: In a 3-phase system, excessive
voltage imbalance between the phases will cause
motors to overheat and eventually fail. Maximum
allowable imbalance is 2%. To determine voltage
imbalance, use recorded voltage measurements in
this formula.
Key: V1, V2, V3 = line voltages as measured
VA (average) = (V1 + V2 + V3) / 3
VD = Line voltage (V1, V2 or V3) that
deviates farthest from average (VA)
Formula: % Voltage Imbalance = [100 x (VA-VD)] / VA
CAUTION
If any of the original wire as supplied with the
appliance must be replaced, it must be replaced
with wiring material having a temperature rating of
at least 105ºC.
WARNING
To prevent injury or death due to electrocution or
contact with moving parts, lock disconnect switch
open.
Most factory supplied electrical components are
pre-wired. To determine what electrical accessories
require additional field wiring, refer to the unit-specific
wiring diagram located on the inside of the unit
control center access door. The low voltage control
circuit is 24 VAC and control wiring should not exceed
0.75ohms.
Refer to Field Control Wiring Length/Gauge table for
wire length maximums for a given wire gauge.
Field Control Wiring Length/Gauge
Total
Wire Length
125 ft. 18
200 ft. 16
300 ft. 14
450 ft. 12
Minimum
Wire Gauge
Control wires should not be run inside the same
conduit as that carrying the supply power. Make sure
that field supplied conduit does not interfere with
access panel operation.
If wire resistance exceeds 0.75 ohms, an industrialstyle, plug-in relay should be added to the unit
control center and wired in place of the remote
switch (typically between terminal blocks R and G
on the terminal strip (refer to Typical Control Center
Components). The relay must be rated for at least
5 amps and have a 24 VAC coil. Failure to comply
with these guidelines may cause motor starters to
“chatter” or not pull in which can cause contactor
failures and/or motor failures.
Model PVe Heat Recovery Unit
9
Typical Control Center Components
1. Main Disconnect (non-fusible, lockable)
2. Motor Starter
3. Motor Starter
4. Power Distribution Blocks
5. 24 VAC Control Transformer
6. 24 VAC Terminal Strip
7. Temperature Sensor with Override (used for
Economizer Mode)
8. Dirty Filter Sensor
9. Dirty Filter Sensor
1
4
5
6
7
Electric Heater Application/Operation
Factory installed electric heaters are optionally
provided in order to provide preheat frost control.
An electric preheater warms the outdoor air prior to
being drawn through the PVe plate heat exchanger.
Electric heaters are available in 208, 230, or 460 VAC.
Refer to heater nameplate for voltage rating.
Preheaters: If an optional preheater is supplied with
the unit, it is installed as a single stage on/off control.
Preheaters are single-point wired at the factory. A
thermocouple type
temperature sensor
is mounted in the
outdoor airstream
after the preheater and
that thermocouple will
switch the preheater
on. See Frost Control
Application/Operation
for typical set points.
If the temperature falls
below the set point
and a pressure drop
sensor is triggered, the
preheater will turn on.
2 3
98
Model PVe Heat Recovery Unit
10
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