Energy recovery COMPONENT rated in
accordance with AHRI/ANSI Standard 1060-2005
and certified to AHRI. Actual performance in
packaged equipment may vary.
®
ERV Unit with Millennium® Packaged Unit
DESCRIPTION
246681-YTG-C-0611
•Reduces cooling load at design temperatures up to 4 tons per
1000 cfm of outside air.
•Reduces heating load up to 2.5 T ons Btuh per 1000 CFM of outside air.
•Dry energy transfer. Moisture in supply (intake) air stream is
transferred to exhaust air stream in a vapor state, eliminating
condensate plumbing from the UERV.
•Attaches directly to the York rooftop units. All mounting equipment is provided.
•Separate fused power supply. (Except Millennium or VR74 or
VR122)
•Filters / mist eliminators are provided on the entering air openings.
•Adjustable support legs are provided.
•Two modes of operation (Pivoting Wheel Models only)
•Recovery mode during normal energy recovery operation.
•True economizer mode when outside sensor calls for
economizer operation (3 - 12.5 ton packaged units
equipped with economizers). U. S. Patent 5,548,970.
•Pivoting wheel models used with packaged unit with economizer. Sequence of operation controlled by economizer controller. (Small Sunline and Predator Only)
•Balancing dampers provided on VR, VH and VU Modules.
(Except Millennium or VR74 and VR122)
•Centrifugal blowers (both intake and exhaust for high static
capability and low sound levels). (Except Millennium, VR74 and
VR122)
•Heavy gauge galvanized steel cabinets corrosion protected with
powder paint process that match York units.
•Fully insulated cabinet.
•AHRI certified internal enthalpy wheel is provided.
•Internal enthalpy wheel made of polymeric material with silica
gel impregnated into the material. The enthalpy wheel has a
five year limited warranty.
•Internal enthalpy wheels are easily cleanable. Large wheels (25
inch diameter and above) are split into easily removable pie
segments. Smaller wheels can be removed from the ERV.
•Continuous operation down to 10 ºF (-12 ºC) without defrost at
indoor relative humidity up to 40%. For temperatures below 10
ºF (-12 ºC), Optional Low Ambient Control Kit is required. Kit
includes temperature sensor to control the ERV before frost
build up can occur on recovery wheel.
®
Note: MAXA-MI$ER
rooftops using 14” high or greater roof curbs.
UERV’s are designed for use with
Note: Predator models ZF/ZH/ZJ/XP* 037-150, with
ERV must use “slab” type economizers and
downflow position.
FOR DISTRIBUTION USE ONLY - NOT TO BE USED AT POINT OF RETAIL SALE
O = Stand Alone Over and Under, Stationary
S = Stand Alone Side by Side
P = Rooftop Pivoting (036-060 & 078-150 only)
020 = 1100 to 1700
028 = 2200 to 2800** 1500 to 2200**
036 = 2800 to 3600
046 = 3400 to 4600
062 = 5500 to 6200** 4800 to 5600**
074 = 6000 to 8000
122 = 8000 to 13000
Blower Speed
M = Medium Speed**
V = Variable Speed
L = Constant Volume
5= 575v-3ph
9= 208/320v-1ph
A12 = 50” Predator ZF/ZH/ZR/XP*102-150, ZJ076-150
B12 = 42” Predator ZF/ZR/XP078-090, ZH0037-090, ZJ/ZR076-150
A15 = Large Sunline ZF180
A25 = Large Sunline ZF210-300, ZJ180-300, XP180-240
A40 = Millinnium 25, 30 and 40 Ton Package
A = No Selection on Rooftop Units
L1 = Low Ambient Kit (LAK)*
L2 = LAK & Motorized Outside Air (MOA)*
L3 = LAK, MOA & Stop-Start-Job (SSJ) (not used on P models)*
L4 = LAK, MOA, SSJ & Pressure Sensor (PS) (not used on P)
L5 = LAK & SSJ (not used on P models)*
L6 = LAK, SSJ & PS (not used on P models)
L7 = LAK & PS
L8 = LAK, MOA and PS
M1 = Motorized Outside Air (MOA)*
M2 = MOA, and Stop Start-Jog (SSJ) (not used on P models)*
M3 = MOA, SSJ and Pressure Sensor (PS) (not used on P models)
M4 = MOA and PS
S1 = Stop-Start-Job (SSJ) (not used on P models)*
S2 = SSJ and Pressure Sensor (PS) (not used on P models)
P1 = Pressure Sensor (PS)
* CFM is ERV wheel rating. This may vary depending on unit cabinet pressure drop.
** These CFM ranges are dependant upon blower motor selection.
YORK UERV MODEL NOMENCLATURE
Unitary Products Group3
246681-YTG-C-0611
APPLICATIONS
Unitized Energy Recovery Ventilators (UERV) are used with
the York rooftop packaged units. The internal wheel provides
sensible and latent energy exchange between the entering
and exhaust air streams of a buildin g. Thi s al l ow s a su bstantial amount of the energy, which is normally lost in the
exhaust air stream to be returned into the entering air. Ideal
applications are areas that have cold or hot temperatures, or
areas that have high humidity or very low humidity (recover
exhaust air from buildings that have humidifiers to add
humidity). Application software is available to provide the
energy and dollar savings for all areas of the United States
and Canada.
PRINCIPLE OF OPERATION
The UERV enthalpy wheel contains parallel layers of a polymeric material that are impregnated with silica gel (desiccant). The wheel is located in the entering (intake) air and
exhaust air streams of the ventilation equipment. As the
wheel rotates through each air stream, the wheel surface
adsorbs sensible and latent energy. In the heating mode, the
wheel rotates to provide a constant transfer of heat from the
exhaust air stream to the colder intake air stream. During the
cooling season, the process is reversed. On units equipped
with an economizer (3 - 12.5 tons), the wheel pivots out of the
air stream to allow economizer to operate normally for "free
cooling" when outdoor temperature and humidity is acceptable. During economizer operation, the UERV exhaust
blower continues to run, providing power exhaust for the system. The intake blower is de-energized during economizer
operation.
AHRI/ANSI STANDARD 1060-2005 FOR AIR-TO-AIR
ENERGY RECOVERY VENTILATION EQUIPMENT
The Air-Conditioning, Heating and Refrigeration Institute
(AHRI) issued Standard 1060-2005 to certify air-to-air energy
recovery ventilators. This standard deals specifically with the
ratings of the Energy Recovery Wheel that is incorporated
into the Energy Recovery Ventilator (ERV). All of the York
ERV's have an AHRI certified energy recovery wheel. The
data shown in the specification charts is the AHRI certified
ratings for the wheel. Actual performance in the ERV may
vary.
Critical Terms for Standard 1060 are as follows:
1.Effectiveness. The measured energy recovery effec-
tiveness not adjusted to account for that portion of the
psychrometric change in the leaving supply air (Station
2) that is the result of leakage of entering exhaust air
(Station 3) rather than exchange of heat or moisture
between the air streams.
2.Net Effectiveness. The measured recovery effective-
ness adjusted to account for that portion of the psychometric change in the leaving supply air (Station 2) that is
the result of leakage of the entering exhaust air (Station
3) rather than exchange of heat or moisture between the
air streams.
3.Exhaust Air Transfer Ratio (EATR). The tracer gas
concentration difference between the leaving supply air
(Station 2) and entering supply (outdoor) air stream (Station 1) divided by the tracer gas concentration in the
entering exhaust (return) air (Station 3) at the 100%
rated air-flow, expressed as a percentage.
4.Outdoor Air Correction Factor (OACF). The entering
supply (outdoor) airflow (Station 1) divided by the measured (gross) leaving supply airflow (Station 2).
ENERGY RECOVERY WHEEL
The heart of the Energy Recovery Ventilator is the Energy
Recovery Wheel (defined by AHRI as a rotary heat
exchanger). The wheel has a patented design of parallel layers of wrapped polymeric material that is impregnated with a
silica gel (desiccant). This unique design makes it the only
truly cleanable wheel on the market today. The small wheels
(30 inch diameter and smaller) are slide out cassettes, and
the larger wheels have pie segments that are removable for
cleaning.
FIGURE 1 - UNITIZED ENERGY RECOVERY
VENTILATOR
4Unitary Products Group
FIGURE 2 - ENERGY RECOVERY WHEEL
246681-YTG-C-0611
CROSS LEAKAGE IN UERV’S (PURGE SECTORS)
to 20% higher to get the desired air intake, and the cost associated with it.
The issue of cross leakage in rotary wheel based UERV's
used in space conditioning applications is often misunderstood. As a result, many systems are installed with purge
sectors and the additional fan capacity required to allow
these sectors to function when in fact they are unnecessary.
A better understanding of the rational for the purge sector,
and its history , allows us to dispense with the purge sector, its
added first cost and continuing cost of operation.
A purge sector minimizes the carry over cross leakage from
the exhaust into the supply (outside air) air stream by shunting a portion of the supply air back into the exhaust air stream
In space conditioning applications, where the ventilation is
operating to maintain acceptable indoor air quality, there are
no contaminants in concentrations large enough to cause
concern. Cross leakage in the UERV system results in a
small amount of the exhaust air, typically less than 5% in balanced airflow, returning to the space. This is not contaminated air, as some would suggest. It is however air that
effectively never left the space. The operation cost of moving
this air is far less than that required for a purge sector. Do not
use the Y ork UER V's in applications that have concentrations
of contaminants.
across the seal separating the exhaust and supply. This is
required in industrial applications where the exhaust carries
contaminants. This typically results in air volume being 15%
match the specified unit. See specification pages for required
curb. Must be ordered separately from UERV.
Stand Alone Balancing Damper - Balancing dampers are
used with VO and VS models when ERV is connected to the
rooftop unit, not to ductwork on the roof.
Roof Curb - A 14 or 24 inch (355 or 610 mm) roof curb is
required to match supply and exhaust openings of the UERV
with the rooftop units. Y ork provides a full line of roof curbs to
Unitary Products Group5
246681-YTG-C-0611
Ventilator
Wheel Type
CFM = 2800
York Unit Cabinet Size
Blower Speed (H for High, M for Medium)
Voltage
Duct Type (A)
Option Code (see list above)
Generation
V
R
028 A12H4AL31
OPTIONAL ACCESSORIES - FACTORY
INSTALLED
Low Ambient Control Kit - Prevents frost formation on
energy wheel heat transfer surfaces by terminating the intake
blower operation when discharge air temperature falls below
a field selectable temperature setting. Intake blower operation resumes operation after temperature rises above the
adjustable temperature differential.
Pressure Sensor - Measurement device on the UERV to
determine airflow across the Wheel.
Motorized Intake Air Damper - Damper mounts in the outdoor air intake hood. It opens when the UERV is energized
and closes when de-energized.
Stop-Start-Jog - Function that rotates the Enthalpy Wheel
(non-pivoting models) on a preset timer to prevent contamination of the wheel during economizer operation.
ERV Option Codes (ex.: VR028A12H4AL3 would be an R28
series high speed 460 volt UERV with a Low Ambient kit,
Motorized Outside Air, and Stop-Start-Jog kit.)
L1 - Low Ambient Kit (LAK) *
L2 - LAK & Motorized. Outside Air (MOA) *
L3 - LAK, MOA, & Stop-Start-Jog (SSJ) *
L4 - LAK, MOA, SSJ, & Pressure Sensor (PS)
L5 - LAK and SSJ *
L6 - LAK, SSJ, and PS
L7 - LAK and PS
L8 - LAK, MOA, and PS
M1 - Motorized Outside Air (MOA) *
M2 - MOA and Stop-S tart-Jog (SSJ) *
M3 - MOA, SSJ, and Pressure Sensor (PS)
NOTE:* denotes only options available for VR074 & VR122.
HOW TO SELECT THE PROPER AIR
CONDITIONING UNIT AND UNITARY ENERGY
RECOVERY VENTILATOR
1.Determine the air conditioning load requirements with
the required amount of outside air without an UERV.
2.Select the proper UERV for the outside air CFM require-
ments and calculate the tonnage reduction through the
York UERV software program.
3.Select the air conditioning unit required by reducing the
load determined in step 1 by the reduction in step 2.
(Example: If the load in Step 1 was 10 tons, and the
reduction in Step 2 was 2.5 tons, select a 7.5 ton unit.)
4.Select the proper UERV based on the select unit. The
York part numbering scheme is as follows:
6Unitary Products Group
246681-YTG-C-0611
TABLE 2: PERFORMANCE - 3 THROUGH 12 1/2 TON UNITS
“R” Series Stationary Wheel for Units without Economizers
York
Packaged Unit
Model No.
Small Sunline
ZF036-060
ZR036-060
XP036-060
(42”)
Short Predator
ZH037-090
ZF078-090
ZJ037-061
ZR037-090
(50”)
Tall Predator
ZF102-150
ZH102-150
ZJ078-150
XP102-150
ZR102-150
Unit
Size
(Tons)
3 - 6
3 - 7.5
6 - 12.5
ERV CFM
Range
300-550VR006A06H
600-1000VR011A06H
300-550VR006B06H
600-1000VR011B12H
11 00-1700VR020B12H
600-1000VR011A12H
11 00-1700VR020A12H
1500-2200VR028A12M
2200-2800VR028A12H
Matching ERV
Model
V oltage &
Phase
110v-1ph1
208/230v-1ph9
208/240v-3ph2
460v-3ph4
208/230v-1ph9
208/230v-3ph2
460v-3ph4
575v-3ph5
208/230v-3ph2
575v-3ph5
208/230v-3ph2
575v-3ph5
208/230v-3ph2
575v-3ph5
208/230v-3ph2
575v-3ph5
208/230v-3ph2
575v-3ph5
208/230v-3ph2
575v-3ph5
208/230v-3ph2
575v-3ph5
Voltage
Code
Nominal AHRI Data (Total
CFM
50065%64%
90073%72%
50065%64%460v-3ph4
90073%72%460v-3ph4
160065%64%460v-3ph4
90073%72%460v-3ph4
160065%64%460v-3ph4
195071%70%460v-3ph4
260065%63%460v-3ph4
Net Effectiveness
HeatingCooling
Note 1: Complete York ERV model number includes the electrical information. Example ZF 060
needing 500 CFM outside of air at 230 volts/3 phase. Model would be a VR006A06H2AAA1.
Unitary Products Group7
246681-YTG-C-0611
TABLE 3: PERFORMANCE - 15 THROUGH 25 TON UNITS
Use this table to determine ventilation and size requirements. Table shows York packaged units and matching ERV model,
Air Flow Range, and AHRI rated Net Effectiveness at 100% of rated CFM.
“R” Series Stationary Wheel for Units without Economizers
York
Packaged Unit
Model No.
Large Sunline
ZF180
ZJ180
ZR180
XP180
Large Sunline
ZJ210-300
ZR240-300
ZF210-300
XP240
Millennium
Z32
Z33
Z34
Note 1:Complete York ERV model number includes the electrical information. Example: ZJ180 needing 2800 CFM
outside of air at 230 volts/3 phase. Model would be a VR028A15H2AAA1.
Note 2:For VR074 and VR122 units used with an economizer must have the Start-Stop-Jog (SSJ) option.
Unit
Size
(Tons)
15
17.5 - 25
25-40
ERV CFM
Range
1500-2200VR028A25H
2200-2800VR028A25H
2800-3600VR036A15H
3400-4600VR046A15H
4800-5600VR062A25M
5500-6200VR062A25H
2200-2800VR028A25H
2800-3600VR036A25H
3400-4600VR046A25H
4800-5600VR062A25M
5500-6200VR062A25H
6000-8000VR074A40*
8000-13000VR122A40*
Matching ERV
Model
Voltage &
Phase
208/230v-3ph2
575v-3ph5
208/230v-3ph2
575v-3ph5
208/230v-3ph2
575v-3ph5
208/230v-3ph2
575v-3ph5
208/230v-3ph2
575v-3ph5
208/230v-3ph2
575v-3ph5
208/230v-3ph2
575v-3ph5
208/230v-3ph2
575v-3ph5
208/230v-3ph2
575v-3ph5
208/230v-3ph2
575v-3ph5
208/230v-3ph4
575v-3ph2
208/230v-3ph2
575v-3ph5
208/230v-3ph2
575v-3ph5
Voltage
Code
Nominal AHRI Data (Total
CFM
195071%70%460v-3ph4
260065%63%460v-3ph4
310065%63%460v-3ph4
390065%63%460v-3ph4
412571%70%460v-3ph4
550065%63%460v-3ph4
260065%63%460v-3ph4
310065%63%460v-3ph4
390065%63%460v-3ph4
412571%70%460v-3ph4
550065%63%460v-3ph5
660065%63%460v-3ph4
1080065%63%460v-3ph4
Net Effectiveness
HeatingCooling
8Unitary Products Group
246681-YTG-C-0611
Enthalpy Wheel
(with removable pie
segments)
Air Blower
(
)
e
Air Blower
(energized)
Air Blower
Fresh Air Damper
(opens during economizer
operation)
local code approval
)
Enthalpy Wheel
Discharge Air Stream
TABLE 4: PERFORMANCE - PIVOTING WHEEL MODELS
“P” Series Pivoting Wheel for Units with Economizers
York
Packaged Unit
Model No.
Small Sunline
ZF036-060
ZR036-060
XP036-060
Short Predator (42”)
ZH037-090
ZF078-090
ZJ037-061
ZR037-090
XP078-090
Tall Predator (50”)
ZF102-150
ZH102-150
ZJ078-150
XP102-150
ZR102-150
Note 1: Complete York ERV model number includes the electrical information. Example ZF 060
Unit
Size
(Tons)
3 - 6
ERV
CFM
Range
600-
1000
600-
1000
7.5 - 8.5
1100-
1700
600-
1000
1100-
6.5 -
12.5
1700
1500-
2200
2200-
2800
needing 800 CFM outside of air at 230 volts/3 phase. Model would be a VP011A06H2AAA1.
2: Predator models ZF/ZH/ZJ/XP* 037-150, with ERV must use “slab” type economizers and downflow
position.
Max.
CFM
Power
Exhaust
Matching
ERV
Model
1900VP011A06H
1900VP011B12H
3000VP020B12H
1900VP011A12H
3000VP020A12H
3450VP028A12M
4200VP028A12H
Voltage &
Phase
Voltage
Code
208/230v-1ph9
208/240v-3ph2
460v-3ph4
575v-3ph5
208/230v-3ph2
575v-3ph5
208/230v-3ph2
575v-3ph5
208/230v-3ph2
575v-3ph5
208/230v-3ph2
575v-3ph5
208/230v-3ph2
575v-3ph5
208/230v-3ph2
575v-3ph5
Nominal AHRI Data (T otal
Net Effectiveness
CFM
HeatingCooling
90073%72%
90073%72%460v-3ph4
160065%64%460v-3ph4
90073%72%460v-3ph4
160065%64%460v-3ph4
195071%70%460v-3ph4
260065%63%460v-3ph4
Pivoted out of Intake and
Outsid
Exhaust
energized
Exhaust
Unit & UERV Disconnect
(provided correct wire size used
for both units and
FIGURE 3 - “P” SERIES PIVOTING WHEEL FOR UNITS W/ECONOMIZERS
Unitary Products Group9
TABLE 5: SPECIFICATIONS AND ELECTRICAL DATA - 300 THROUGH 550 CFM ERV’S
VS006 - S/S Stand Alone Stationary
Model Numbers
Line Voltage - 60hz115v-1ph208/230v/460-1ph 208/230v/460-3ph
Motor - hp / type0.25 / PSC
Wheel Size (dia x width) - in5.5 x 6.3
Note: 1: A st epdown transformer is provided to stepdown high voltage primary to 115 volt secondary.
Motor Speed - rpm1780
Motor Speed(s)2
Bearing TypeSleeve
Full Load Amps3.8
Service Factor1.1
Motor - hp0.25 / PSC
Wheel Size (dia x width) - in5.5 x 6.3
Motor Speed - rpm1780
Motor Speed(s)2
Bearing TypeSleeve
Full Load Amps-Stationary3.8
Service Factor1.1
Potential Volts115
Motor Speed (RPM)/Wheel (RPM)1050/68
Full Load Amps0.7
MCA8.7
OCPD10
Wheel Depth2
Wheel Diameter19.3
Construction / Media TypeOne Piece / Polymeric
Nominal Airflow CFM500 @ .6
EATR - -0.50 H
EATR - 0.00 H
EATR - +0.50 H
OACF - -0.50 H
OACF - 0.00 H
OACF - +0.50 H
Motor Speed - rpm1120 / 960 / 8501725
Motor Speed(s)3Adjustable Sheave
Bearing TypeSleeveBall
Full Load Amps3.43.81.91.4
Service Factor11.15
Motor - hp Stationary.5 / PSC1.0 / Belt
Motor - hp Pivoting.5 / PSC1.5 / Belt
Wheel Size (dia x width) - in10 x 6 AT9 x 9
Motor Speed - rpm1120 / 960 / 8501725
Air
Motor Speed(s)3Adjustable Sheave
Bearing TypeSleeveBall
Full Load Amps-Stationary3.43.41.51.53.81.91.4
Full Load Amps-Pivoting3.43.41.51.55.62.82.0
Service Factor11.15
Potential Volts208 / 230208 / 230
Motor Speed (RPM)/Wheel
(RPM)
Data
Full Load Amps0.30.3
MCA - Stationary8.258.254.44.48.854.583.45
OCPD - Stationary1010661265
Shipping Weight - lbs.318425
Net Weight - lbs.245345
Note: 1. Pivoting electrical data applies to VP models only.
O9.30%7.80%
2
O0.70%0.40%
2
O0.00%0.00%
2
O0.97%0.97%
2
O1.19%1.16%
2
O1.34%1.29%
2
1050/561050/46
VR020 - Rooftop Stationary
VP020 - Rooftop Pivoting
VO020 - O/U Stand Alone
VS020 - S/S Stand Alone
Unitary Products Group11
TABLE 7: SPECIFICATIONS AND ELECTRICAL DATA - 150 0 THROUGH 2800 CFM ERV’S
246681-YTG-C-0611
Model Numbers
* VP028 - Rooftop Pivoting
VS028 - S/S Stand Alone
VO028 - O/U Stand Alone
Line Voltage - 60hz208/230v-3ph460v-3ph575v-3ph208/230v-3ph460v-3ph575v-3ph
Motor - hp / type1.5 / Belt2 / Belt
Wheel Size (dia x width) - in10 x 1010 x 10
* VR028 - Rooftop Stationary
Fresh Air
Blower
Exhaust
Blower
Wheel
Electrical
Data
Total
Electrical
Wheel
Data
Enthalpy
Wheel
AHRI
Rating
Data
Total
Effective-
ness
Effective-
ness
CurbA/C Unit Curb Height - in24 on A12, 14 on A15 & A2524 on A12, 14 on A15 & A25
Weights
Note: Pivo ting electrical data applies to VP models only.
Motor Speed - rpm17251725
Motor Speed(s)Adjustable SheaveAdjustable Sheave
Bearing TypeBallBall
Full Load Amps5.62.827.03.52.4
Service Factor1.151.15
Motor - hp Stationary1.5 / Belt2 / Belt
Motor - hp Pivoting3 / BeltWheel Size (dia x width) - in10 x 1010 x 10
Motor Speed - rpm17251725
Air
Motor Speed(s)Adjustable SheaveAdjustable Sheave
Bearing TypeBallBall
Full Load Amps-Stationary5.62.827.03.52.4
Full Load Amps-Pivoting94.43.6--Service Factor1.151.15
Motor - hp (1 phase)0.170.17
Potential Volts200-208 / 230200-208 / 230
Motor Speed (RPM)/Wheel (RPM)825/58825/58
Full Load Amps0.60.6
MCA - Stationary13.26.95.116.48.56
OCPD - Stationary2010720107
MCA - Pivoting17.58.97.1--OCPD - Pivoting251210--Wheel Depth x Diameter - in3 x 37.7593 x 37.759
Construction / Media TypeSegmented Pies / PolymericSegmented Pies / Polymeric
Nominal Airflow CFM2600 @ .952600 @ .95
EATR - -1.00 H
EATR - 0.00 H
EATR - +1.00 H
OACF - -1.00 H
OACF - 0.00 H
OACF - +1.00 H
Shipping Weight - lbs.470470
Net Weight - lbs.395395
* Electric data is for (A12) ZH/ZF/ZJ 078-150 and XP 078-150 only.
** Electric da ta is for (A15 and A25) ZH/ZF/ZJ 180-300 and XP 180 and 240 only.
12Unitary Products Group
246681-YTG-C-0611
TABLE 8: SPECIFICATIONS AND ELECTRICAL DATA - 2800 THROUGH 3600 CFM ERV’S
Model Numbers
VR036 - Rooftop Stationary
VS036 - S/S Stand Alone
VO036 - O/U Stand Alone
Line Voltage - 60hz208/230v-3ph460v-3ph575v-3ph208/230v-3ph460v-3ph575v-3ph
Motor - hp / type2 / Belt2 / Belt
Wheel Size (dia x width) - in12 x 912 x 9
Fresh Air
Blower
Motor Speed - rpm17251725
Motor Speed(s)Adjustable SheaveAdjustable Sheave
Bearing TypeBallBall
Full Load Amps7.03.53.27.03.52.4
Service Factor1.151.15
Motor - hp Stationary3 / Belt2 / Belt
Wheel Size (dia x width) - in12 x 912 x 9
Exhaust Air
Blower
Motor Speed - rpm17251725
Motor Speed(s)Adjustable SheaveAdjustable Sheave
Bearing TypeBallBall
Full Load Amps-Stationary7.03.53.27.03.52.4
Service Factor1.151.15
Motor - hp (1 phase)0.500.50
Wheel
Electrical
Data
Potential Volts200-208 / 230200-208 / 230
Motor Speed (RPM)/Wheel
(RPM)
1725/641725/64
Full Load Amps1.21.2
Total
Electrical
Wheel
Data
MCA - Stationary16.48.66.616.48.66.6
OCPD - Stationary2512925129
Wheel Depth x Diameter - in3 x 41.8253 x 41.825
Construction / Media TypeSegmented Pies / PolymericSegmented Pies / Polymeric
Nominal Airflow CFM3100 @ .93100 @ .9
O4.90%4.90%
2
O1.30%1.30%
2
O0.30%0.30%
2
O0.99%0.99%
2
O1.07%1.07%
2
O1.12%1.12%
2
Enthalpy
Wheel AHRI
Rating Data
EATR - -1.00 H
EATR - 0.00 H
EATR - +1.00 H
OACF - -1.00 H
OACF - 0.00 H
OACF - +1.00 H
Shipping Weight - lbs.571571
Net Weight - lbs.475475
Unitary Products Group13
TABLE 9: SPECIFICATIONS AND ELECTRICAL DATA - 340 0 THROUGH 5600 CFM ERV’S
246681-YTG-C-0611
Model NumbersVS046 - S/S Stand Alone
VR046 - Rooftop Stationary
VO046 - O/U Stand Alone
Line Voltage - 60hz208/230v-3ph460v-3ph575v-3ph208/230v-3ph460v-3ph575v-3ph
Motor - hp / type5 / Belt3 / Belt
Wheel Size (dia x width) - in12 x 1212 x 12
Fresh Air
Blower
Motor Speed - rpm17251725
Motor Speed(s)Adjustable SheaveAdjustable Sheave
Bearing TypeBallBall
Full Load Amps12.86.45.19.44.33.4
Service Factor1.151.15
Motor - hp Stationary5 / Belt3 / Belt
Wheel Size (dia x width) - in12 x 1212 x 12
Exhaust Air
Blower
Motor Speed - rpm17251725
Motor Speed(s)Adjustable SheaveAdjustable Sheave
Bearing TypeBallBall
Full Load Amps-Stationary12.86.45.194.43.6
Service Factor1.151.15
Motor - hp (1 phase)0.50.5
Wheel
Electrical
Data
Potential Volts200-208 / 230200-208 / 230
Motor Speed (RPM)/Wheel
(RPM)
1075/571075/57
Full Load Amps1.21.2
Total
Electrical
Wheel
Data
MCA - Stationary3015.61222119.1
OCPD - Stationary402515301512
Wheel Depth x Diameter - in3 x 46.7763 x 46.776
Construction / Media TypeSegmented Pies / PolymericSegmented Pies / Polymeric
Nominal Airflow CFM3900 @ .953900 @ .95
O4.40%4.40%
2
O1.10%1.10%
2
O0.20%0.20%
2
O0.99%0.99%
2
O1.06%1.06%
2
O1.11%1.11%
2
Enthalpy
Wheel AHRI
Rating Data
EATR - -1.00 H
EATR - 0.00 H
EATR - +1.00 H
OACF - -1.00 H
OACF - 0.00 H
OACF - +1.00 H
Shipping Weight - lbs.920920
Net Weight - lbs.805805
14Unitary Products Group
246681-YTG-C-0611
TABLE 10: SPECIFICATIONS AND ELECTRICAL DATA - 5500 THROUGH 6200 CFM ERV’S
Model Numbers
VR062 - Rooftop Stationary
VO062 - O/U Stand Alone
VS062 - S/S Stand Alone
Line Voltage - 60hz208/230v-3ph460v-3ph575v-3ph208/230v-3ph460v-3ph575v-3ph
Motor - hp / type5 / Belt5 / Belt
Wheel Size (dia x width) - in12 x 1212 x 12
Fresh Air
Blower
Motor Speed - rpm17251725
Motor Speed(s)Adjustable SheaveAdjustable Sheave
Bearing TypeBallBall
Full Load Amps157.45.81575.8
Service Factor1.151.15
Motor - hp Stationary5 / Belt5 / Belt
Wheel Size (dia x width) - in12 x 1212 x 12
Exhaust Air
Blower
Motor Speed - rpm17251725
Motor Speed(s)Adjustable SheaveAdjustable Sheave
Bearing TypeBallBall
Full Load Amps-Stationary14.875.114.875.1
Service Factor1.151.15
Motor - hp (1 phase)0.50.5
Wheel
Electrical
Data
Potential Volts200-208 / 230200-208 / 230
Motor Speed (RPM)/Wheel
(RPM)
1075/541075/54
Full Load Amps1.22.7
Total
Electrical
Wheel
Data
MCA - Stationary34.817.513.634.817.513.6
OCPD - Stationary402520402520
Wheel Depth x Diameter - in3 x 52.0263 x 52.026
Construction / Media TypeSegmented Pies / PolymericSegmented Pies / Polymeric
Nominal Airflow CFM5500 @ .955500 @ .95
O4.00%4.00%
2
O1.00%1.00%
2
O0.20%0.20%
2
O0.99%0.99%
2
O1.06%1.06%
2
O1.10%1.10%
2
Enthalpy
Wheel AHRI
Rating Data
EATR - -1.00 H
EATR - 0.00 H
EATR - +1.00 H
OACF - -1.00 H
OACF - 0.00 H
OACF - +1.00 H
Motor Speed(s)Adjustable SheaveAdjustable Sheave
Bearing TypeBallBall
Full Load Amps14.87522.49.77.8
OCPD2097301510
Service Factor1.151.15
Motor - hp (3 phase)0.250.250.250.250.250.25
Motor Speed (RPM)/Wheel
(RPM)
850/49850/51
Full Load Amps2.51.20.952.51.20.95
OCPD322322
MCA34.916.612.75222.619
OCPD502015703025
Wheel Depth x Diameter - in3 x 583 x 74
Construction / Media TypeSegmented Pies / PolymericSegmented Pies / Polymeric
Nominal Airflow CFM6600 @ .9510800 @ .95
EATR - -1.00 H
EATR - 0.00 H
EATR - +1.00 H
OACF - -1.00 H
OACF - 0.00 H
OACF - +1.00 H
300-55023.25 x 32.534.8324.7524.638.0020.002.002.252.328.00
30.25 x 4344.7532.1333.5012.0027.00
Features and Notes
4. Roof curbs are available for the UERV's.
600-1000
UERV with Horizontal Ductwork
UERV Roof Curbs
Dimensional DataUERV Data
2.605.002.5611.00
18.3239.508.003.59
18.32
2800-3600
41.81 x 55.75
4.005.3152.2542.6343.5614.00
20.3252.3837.2537.5012.0030.004.504.003.63
8.19
57.3716.50
32.004.75
8.19
39.508.19
57.3716.5060.00
54 x 55.7560.0058.88
60.0052.69
46.69
1100-1700
1500-2800
3400-460047.81 x 55.75
41 x 49.5
35.5 x 52.75
18.32
8.009.6818.32
8.006.59
4800-620057.3716.5039.50
Ductwork Field
Supplied
A
F
D
E
B
C
B
A
J
K
VO006
VO011
VO020
VO028
VO036
VO046
VO062
5. CFM is based on 0 external static pressure.
VO006
VO011
VO020
VO028
VO036
VO046
VO062
S
M
246681-YTG-C-0611
D
C
14
H
(
FIGURE 9 - STAND ALONE UERV’S FOR OVER AND UNDER DUCT ARRANGEMENTS
22Unitary Products Group
246681-YTG-C-0611
GUIDE SPECIFICATIONS
Prepared for the guidance of architects, consulting engineers, and mechanical contractors.
GENERAL
Furnish and install _____________ mechanical cooling system, complete with a Unitized Energy Recovery Ventilator
(UERV).
APPROVALS
The Unitized Energy Recovery Ventilator will contain an
energy recovery component rated in accordance with AHRI/
ANSI Standard 1060-2005 with ratings certified by AHRI.
Cabinet
UERV shall be designed to attach directly to the a/c (rooftop,
upflow, horizontal) unit. It shall be G90 galvanized material
with a powdered enamel paint finish electrostatically bonded
to the metal. Cabinet panels where conditioned air is handled
shall be fully insulated to prevent sweating and minimize
sound. Openings shall be provided for power connections.
Lifting devices will be provided for rigging. Test ports shall be
provided so airflow can be measured across the energy
recovery wheel.
Intake Air Blower (direct drive)
UERV shall contain a centrifugal blower. All UERV's will be
equipped with direct drive PSC blower motors. The motor will
be multiple speed and will be individually controlled. Airflow
will also be adjustable by means of a damper on the intake air
opening. Blowers and motors will be removable through
means of a connecting plug for ease of servicing.
Intake Air Blower (belt drive)
UERV shall contain a centrifugal blower. It shall have ball
bearings and adjustable belt drive. Motor mount base shall
permit ease of motor changeover and belt tension adjustment. On pivoting wheel models, supply blower will be deenergized during economizer operation. (Except for VR074
and VR122.)
Exhaust Air Blower (direct drive)
UERV shall contain a centrifugal blower. All UERV's will be
equipped with direct drive PSC blower motors. The motor will
be multiple speed and shall be individually controlled. Blowers and motors will be removable through means of a connecting plug for ease of servicing. On pivoting wheel models,
blower shall be sized to provide power exhaust during economizer operation.
Exhaust Air Blower (belt drive)
sized to provide power exhaust during economizer operation.
Where single blowers cannot provide adequate exhaust, two
blowers will be utilized. One blower is energized during
energy recovery mode, and both blowers are energized during economizer mode.
Energy Recovery Wheel
The energy recovery device shall be a rotary heat exchanger
per AHRI Standard 1060 description. The device will be an
enthalpy wheel coated with a silica gel desiccant by a patented process without the use of binders or adhesives which
may plug the desiccant aperture. The substrate shall be a
lightweight polymer. Desiccant shall not dissolve or deliquesce in the presence of water or high humidity. The wheel
shall be easily cleanable with standard coil cleaning solution.
On UERV's Series 20 and less, the wheel will easily be
removable from the cabinet for cleaning. On UERV's Series
20 and above, the wheel will be provided with removable segments for cleaning and maintenance. All diameter and perimeter seals shall be provided. The energy recovery cassette
shall be Underwriters Laboratories Recognized Component
for electrical and fire safety.
Balancing Dampers
Balancing dampers will be provided for all VR UERV’s. These
dampers will be mounted inside the rooftop air conditioning
unit to adjust for the amount of exhaust air on packaged units.
On pivoting wheel models, the unit econ o mi z er becomes the
balancing damper. Upflow and horizontal ERVs' will have the
balancing damper provided in the ERV. Optional on VO and
VS UERV’s when connected to rooftop units. (Except for
VR074 and VR122.)
Barometric Relief Dampers
Barometric relief dampers will be provided in the exhaust air
hood to prevent air infiltration when the UERV is de-energized.
ERV Support
All UERV's will be provided with support legs attached to the
cabinet to support the intake and exhaust end of the ERV
unit. Horizontal ERV's will be provided with support brackets
for hanging.
Filters
All units shall be provided with mist eliminator type filters in
the intake air hood.
Power Connection
The UERV shall be provided with a single point power connection for high voltage.
UERV shall contain a centrifugal blower. It shall have ball
bearings and adjustable belt drive. Motor mount base shall
permit ease of motor changeover and belt tension adjustment. On pivoting wheel models, exhaust blowers shall be
Unitary Products Group23
OPTIONS
Optional UERV Equipment Support
246681-YTG-C-0611
Furnish and install the optional equipment support for the
intake and exhaust end of the unit.
Optional Roof Curb
Furnish and install the optional roof mounting frame to maintain proper height above the roof.
Optional Low Ambient Kit
Furnish and install the optional low ambient kit to prevent
frost formation on the energy recovery wheel.
Optional Motorized Intake Air Damper
Furnish and install the optional motorized intake air damper.
Optional Stop-Start-Jog
On units without economizers furnish and install the optional
stop-start-jog controls.
SEQUENCE OF OPERATION:
Fixed Models - Normal Operation
1.The space thermostat sends a signal to the RTU for cooling, heating or fan only operation.
2.The ERV is activated simultaneously with the supply
blower of the RTU. The intake blower, the exhaust
blower, and the wheel rotation motor of the ERV are activated. These motors will remain energized as long as
the supply blower on the RTU is energized. The RTU is
in standard (non-economizer) mode.
3.If the optional motorized fresh air damper in the outside
air intake of the ERV is present, it opens and the ERV is
energized.
4.If the optional low ambient kit is present, and the temperature leaving the exhaust side of the wheel drops below
the field adjusted set point on the temperature sensor of
the low ambient kit, the optional motorized fresh air
damper will close and the intake blower will de-energize.
The exhaust air blower and wheel rotation motor will continue to operate. When the temperature sensor has a
sixteen-degree rise, the wheel is defrosted and the
optional motorized damper will open and the fresh air
blower will reactivate.
2.The ERV is activated with the supply blower of the RTU.
The intake blower, the exhaust blower, and the wheel
rotation motor of the ERV are activated. These motors
will remain energized as long as the supply blower on
the RTU is energized and the RTU is in standard (noneconomizer) mode.
3.If the optional motorized fresh air damper in the outside
air intake of the ERV is present, it opens and the ERV is
energized.
4.If the optional low ambient kit is present, and the temperature leaving the exhaust side of the wheel drops below
the field adjusted set point on the temperature sensor of
the low ambient kit, the optional motorized fresh air
damper will close and the intake blower will de-energize.
The exhaust air blower and wheel rotation motor will continue to operate. When the temperature sensor has a
sixteen-degree rise, the wheel is defrosted and the
optional motorized damper will open and the fresh air
blower will reactivate.
Pivoting Models - Economizer Operation
1.The space thermostat sends a signal to the RTU for cooling operation.
2.The outdoor air sensor for the RTU senses the outdoor
air and determines it is appropriate for economizer operation.
3.As the economizer outside air dampers open, the ERV
economizer end switch is activated sending a signal to
the ERV that the system is in the economizer mode.
4.The intake blower, the exhaust blower and the wheel
rotation motor all deactivate for up to two minutes. The
optional motorized fresh air damper (if present) also
closes.
5.The ERV enthalpy wheel pivots out of the air stream and
the bypass dampers along each side of the intake blower
open.
6.After a time delay to allow the wheel to pivot out of the
airstream and the bypass dampers to open, the optional
motorized fresh air damper opens to allow for full economizer operation, and the exhaust blower is reactivated to
provide power exhaust for the system.
Pivoting Models - Normal Operation
1.The space thermostat sends a signal to the RTU for cooling, heating or fan only operation.
24Unitary Products Group
246681-YTG-C-0611
UERV TROUBLESHOOTING GUIDE
UERV BELOW 600 CFM WITH ST A TIONARY WHEEL
(NO ECONOMIZER)
UERV will not operate.
1.Quick check items.
a.Verify S51 door switch is closed. The switch must be
in the closed position to power the A130 circuit
board.
b.Verify the A130 circuit board switch SW1 Power is in
the “on” position.
c.Verify 24 volts to A130 circuit board terminals TB1
“G” and “C” if in the cooling mode, or “W” and “C” if
in the heating mode. The terminals must be powered to allow any blower relays / contactors to operate.
2.Verify high voltage power to UERV.
a.Verify 110 volts for UERV to L1 and L2 on TB2 on
the A130 board.
b.Verify the F1 fuse is good. Replace any bad fuses.
c.Verify that the T28 step down transformer on 208,
230, and 460 volt units have the voltage correctly
applied to the correct transformer terminals.
UERV has power, but the enthalpy wheel does not spin.
1.Check wheel belt is in place and tight.
2.Verify the A130 circuit board switch SW1 Power is in the
"on" position.
3.Verify the A130 circuit board terminals Wheel "1" and "2"
are outputting 110 volts to B28 wheel motor through J/
P150 plug assembly.
4.Verify B28 wheel motor C23 capacitor is good. Replace
the capacitor if it is bad.
5.If the optional Stop, Start, Jog (SSJ) feature is installed,
verify that the temperature setpoint on the SSJ does not
have the wheel stopped.
6.If all of the above are operational, the wheel motor is
bad. Replace it with new motor.
3.Verify B26 wheel motor C25 capacitor is good. Replace
the capacitor if it is bad.
4.If all of the above are operational, the exhaust motor is
bad. Replace it with new motor.
UERV has power, but the fresh air blower does not
operate.
1.Verify the A130 circuit board switch SW1 Power is in the
"on" position.
2.Verify the A130 circuit board terminals Fresh "1” and "3"
if in high speed operation, or "1” and "2" if in low speed
operation are outputting 110 volt s to B27 fresh air blower
motor though J/P148 plug assembly.
3.On units equipped with the optional low ambient control,
verify that the A130 circuit board TB3 terminals marked
"low ambient" are closed. The low ambient control will
stop the fresh air motor operation and close the optional
outside air damper if it senses conditions for frost on the
UERV wheel. The "low ambient" terminals can be
jumped together to verify if the low ambient control has
the fresh air blower stopped.
4.Verify B27 wheel motor C26 capacitor is good. Replace
the capacitor if it is bad.
5.If all of the above are operational, the fresh air motor is
bad. Replace it with new motor.
UERV has power, but the optional motorized fresh air
damper does not open.
1.Verify 24 volts to A130 circuit board terminals TB1 "G"
and "C" if in the cooling mode, or "W" and "C" if in the
heating mode.
2.Verify the A130 circuit board switch SW1 Power is in the
"on" position.
3.Verify 24 volts to B30 motorized outdoor air motor
through J/P160 plug assembly.
4.If all of the above are operational, replace the outdoor air
damper motor.
UERV ABOVE 600 CFM WITH ST ATIONARY WHEEL
(NO ECONOMIZER)
UERV has power, but the exhaust blower does not
operate.
1.Verify the A130 circuit board switch SW1 Power is in the
"on" position.
2.Verify the A130 circuit board terminals Exhaust "1” and
"3” if in high speed operation, or "1” and "2" if in low
speed operation are outputting 110 volts to B26 exhaust
blower motor though J/P151 plug assembly.
Unitary Products Group25
UERV will not operate.
1.Quick check items.
a.Verify S51 door switch is closed. The switch must be
in the closed position to power the A130 circuit
board.
246681-YTG-C-0611
b.Verify 24 volts to A130 circuit board terminals
XFORMER "+" and "-". The terminals must be powered to allow blower contactors to operate.
c.Verify 24 volts to A130 circuit board terminals TB 37
numbers "1" and "3". T erminal "1" is the hot and "3"
is the common side of the power source fr om activa tion power source (a/c unit, energy management
control, etc.). Typically, "1" would be from the blower
contactor on an a/c unit.
2.Verify high voltage power to UERV.
a.Check for correct voltage for UERV to L1 and L2 on
1-phase units.
b.Check for correct voltage for UERV to L1, L2, and
L3 on 3-phase units.
c.Verify the F29 fuses are good. Replace any bad
fuses.
d.Verify that the T27 transformer has the UERV volt-
age correctly applied to the correct transformer terminals.
UERV has power, but the enthalpy wheel does not spin.
1.Check wheel belt is in place and tight.
2.Verify the A130 circuit board terminals Exhaust "A" (hot)
and "B" (common) are outputting 24 volts to K163 contactor terminal "A" and "B" and that the contacts are
closed.
3.Verify power to B28 wheel motor.
4.Verify B28 wheel motor C23 capacitor is good. Replace
the capacitor if it is bad. (Except VR074 to VR122)
5.If the optional Stop, Start, Jog (SSJ) feature is installed,
verify that the timer on the SSJ does not have the wheel
stopped.
6.If all of the above are operational, the wheel motor is
bad. Replace it with new motor.
UERV has power, but the exhaust blower does not
operate.
1.Check that the blower belt is in place and tight on belt
drive models. If it is loose, tighten it. If it is broken replace
it.
2.Verify the A130 circuit board terminals Exhaust "A" (hot)
and "B" (common) are outputting 24 volts to K163 contactor terminal "A" and "B", and that the contacts are
closed.
3.Verify power to B26 exhaust blower motor.
4.On direct drive models, verify B26 wheel motor C25
capacitor is good. Replace if necessary.
5.If all of the above are operational, the exhaust motor is
bad. Replace it with new motor.
UERV has power, but the fresh air blower does not
operate.
1.Check that the blower belt is in place and tight on belt
drive models. Tighten it if it is loose. Replace it if it is broken.
2.Verify the A130 circuit board terminals Fresh "A" (hot)
and "B" (common) are outputting 24 volts to K164 contactor terminal "A" and "B", and that the contacts are
closed.
3.Verify power to B27 fresh air blower motor though J/
P148 plug assembly.
4.On direct drive models, verify B27 wheel motor C26
capacitor is good. Replace if necessary.
5.On units equipped with the optional low ambient control,
verify that the circuit on the A130 circuit board terminal
"5" and "6" is closed. The low ambient control will stop
the fresh air motor operation and close the optional outside air damper if it senses frost on the UERV wheel.
Terminal "5" and "6" can be jumped to gether to verify if
the low ambient control has the fresh air blower stopped.
6.If all of the above are operational, the fresh air motor is
bad. Replace it with new motor.
UERV has power, but the optional motorized fresh air
damper does not open.
1.Verify 24 volts to the A130 circuit board terminals
XFORMER "+" and "-".
2.Verify 24 volts to A130 circuit board terminals TB 37
numbers "1" and "3". T erminal "1" is the hot and "3" is the
common side of the power source from activation power
source (a/c unit, energy management control, etc.). Typically, "1" would be from the blower contactor on an a/c
unit.
3.Verify 24 volts to B30 motorized outdoor air motor
through J/P160 plug assembly.
4.If all of the above are operational, replace the outdoor air
damper motor.
UERV ABOVE 600 CFM WITH PIVOTING WHEEL
(USED WITH ECONOMIZER)
UERV will not operate.
1.Quick check items.
a.Verify S51 door switch is closed. The switch must be
in the closed position to power the A130 circuit
board.
26Unitary Products Group
246681-YTG-C-0611
b.Verify 24 volts to A130 circuit board terminals
XFORMER "+" and "-". The terminals must be powered to allow any blower relays / contactors to operate.
c.Verify 24 volts to A130 circuit board terminals TB 37
numbers "1" and "3". T erminal "1" is the hot and "3"
is the common side of the power source fr om activa tion power source (a/c unit, energy management
control, etc.). Typically, "1" would be from the blower
contactor on an a/c unit.
2.Verify high voltage power to UERV.
a.Check correct voltage for UERV to L1 and, L2 on 1-
phase units.
b.Check for correct voltage to L1, L2, and L3 on 3-
phase units.
c.Verify the F29 fuses are good. Replace any bad
fuses.
d.Verify that the T27 transformer has the UERV volt-
age correctly applied to the correct transformer terminals.
UERV has power, but the enthalpy wheel does not spin.
1.Check wheel belt is in place and tight.
2.Verify the A130 circuit board terminals Exhaust 1 "A"
(hot) and "B" (common) are outputting 24 volts to K163
contactor terminal "A" and "B" and that the contacts are
closed.
3.Verify power to B28 wheel motor through J/P150 plug
assembly.
a.If there is no power on the T1 leg of the motor (pivot-
ing models only) verify that the S110 switch located
inside the B29 damper motor is in the closed position.
4.Verify B28 wheel motor C23 capacitor is good. Replace
the capacitor if it is bad.
5.If all of the above are operational, the wheel motor is
bad. Replace it with new motor.
UERV has power, but the exhaust blower does not
operate.
1.Check that the blower belt is in place and tight. If it is
loose, tighten it. If it is broken replace it.
4.On direct drive models, verify B26 wheel motor C25
capacitor is good. Replace if necessary.
5.If all of the above are operational, the exhaust motor is
bad. Replace it with new motor.
UERV has power, but the fresh air blower does not
operate.
1.Energy Recovery Mode of operation.
a.Check that the blower belt is in place and tight on
belt drive models. Tighten it if it is loose. Replace it if
it is broken.
b.Verify the A130 circuit board terminals Fresh "A"
(hot) and "B" (common) are outputting 24 volts to
K164 contactor terminal "A" and "B", and that the
contacts are closed.
c.Verify power to B27 fresh air blower motor though J/
P148 plug assembly.
d.On units equipped with the optional low ambient
control, verify that the circuit on the A130 circuit
board terminal "5" and "6" is made. The low ambient
control will stop the fresh air motor operation and
close the optional outside air damper if it senses
frost on the UERV wheel. Terminal "5" and "6" can
be jumped together to verify if the low ambient control has the fresh air blower stopped.
e.On direct drive models, verify B27 wheel motor C26
capacitor is good. Replace if necessary.
f.If all of the above are operational, the fresh air motor
is bad. Replace it with new motor.
2.Economizer Mode of operation.
a.The fresh air blower is not operational in the econo-
mizer mode.
UERV has power, but the wheel does not rotate out of
airstream during economizer operation.
1.Check the linkage from the B29 damper motor to the
UERV wheel.
2.Verify shipping retainers are removed.
3.Verify the S122 economizer end switch is closed. The
switch is located on the damper and closes when the
damper moves from minimum position to the economizer
position (field adjustable).
2.Verify the A130 circuit board terminals Exhaust 1 "A"
(hot) and "B" (common) are outputting 24 volts to K163
contactor terminal "A" and "B", and that the contacts are
closed.
3.Verify power to B26 exhaust blower motor though J/P151
plug assembly.
Unitary Products Group27
4.Verify the B29 damper motor has 24 volts to terminals
"B" and "T1" through J/P160 plug assembly
5.If all of the above are operational, replace the damper
motor.
UERV has power, but the optional motorized fresh air
damper does not open.
1.Verify 24 volts to the A130 circuit board terminals
XFORMER "+" and "-".
2.Verify 24 volts to A130 circuit board terminals TB 37
numbers "1" and "3". Terminal "1" is the "hot" and "3" is
the "common" side of the power source from activation
power source (a/c unit, energy management control,
etc.). Typically, "1" would be from the blower contactor
on an a/c unit.
3.Verify 24 volts to B30 motorized outdoor air motor
through J/P160 plug assembly.
4.If all of the above are operational, replace the outdoor air
damper motor.