Reznor XBWS Installation Manual

INSTALLATION INSTRUCTIONS

FORM RZ-NA-I-XBWS-AQ20

SUPERCEDES 09-27-13

MAY 29, 2014

SXX-2ZERV

EN ERGY RE COV ERY VEN TI LA TOR

INSTALLATION INSTRUCTIONS FOR ROOFTOP STAND ALONE

ENERGY RECOVERY UNIT IN SIDE BY SIDE DESIGN

Energy recovery COMPONENT certified
to the AHRI Air-to-Air Energy Recovery
Ventilation Equipment Certification
Program in accordance with AHRI
Standard 1060-2000. Actual performance
in packaged equipment may vary.

I - Ship ping and Pack ing List

Package contains:

1 — Energy Recovery Ventilator Assembly

I I - Ship ping Dam age

Check unit for shipping damage. Receiving party should
contact last carrier immediately if shipping damage is
found.

III - Gen eral

These instructions are intended as a general guide and do
not supersede local codes in any way. Authorities having
jurisdiction should be consulted before installation.

IV - Re quire ments

When installed, the unit must be electrically wired and
grounded in accordance with local codes or, in absence of
local codes, with the current National Electric Code,
ANSI/NFPA No. 70.

V - Ap pli ca tion

These Energy Recovery Ventilators (ERV) are used in a
down discharge manner equipped with field provided
balancing damper assembly through the roof. A roof
curb must be provided to Rooftop Systems specifications.
These wheels conserve energy by mixing warmer air with
cooler air in the following manner:

Re cov ery Wheel Mode

The Recovery Wheel mode is accomplished by two
blowers providing continuous exhaust of stale indoor air
and replacement by equal amount of outdoor air. Energy
recovery is achieved by slowly rotating the energy
recovery wheel within the cassette frame work. In winter,
the ERV adsorbs heat and moisture from the exhaust air
stream during one half of a complete rotation and gives
them back to the cold, drier intake air supply during the
other half rotation. In summer, the process is automatically
reversed. Heat and moisture are absorbed from incoming
fresh air supply and transferred to the exhaust air stream.
This process allows outdoor air ventilation rates to be
increased by factors of three or more without additional
energy penalty or increase in size of heating or air
conditioning systems.

VI - Rig ging Unit For Lift ing

1. Maximum weight of unit is — Varies per Series
{300-1200 Lbs.} (Crated)

2. Remove crating.

Applies To Model XBWS When Used With Option AQ20

Side By Side Design

ETL Certified per UL 1995
and CSA 22.2

3. All panels must be in place for rigging.

4. Remove hood assemblies from door marked filter
access.

5. Place 2" filter in filter rack and replace filter access
door.

6. Roof curb gasket must be applied to all top surfaces of
the curb. (Refer to roof curb installation instruction.)

7. Forklift channels must be removed from the base of
ERV before setting unit on curb. See Figure 1.

8. Position unit on roof curb and provide service access
to ERV control access door and wheel.

WARNING

Electric shock hazard. Can cause injury
or death. Before attempting to perform
any service or maintenance, turn the
electrical power to unit OFF at
disconnect switch(es). Unit may have
multiple power supplies.

CAUTION

Danger of sharp metallic edges. Can cause injury.
Take care when servicing unit to avoid accidental
contact with sharp edges.

FIGURE 1

FORKLIFT CHANNELS

PAGE 1

VII - In stal la tion
Fresh Air Hood As sem bly (See Fig ure 2)

1. Secure hood sides (A and C) to Hood top (B) using the
supplied #10 x ½ screws.

2. Secure filter channels (F and D) to hood sides using
the supplied #10 x ½ screws.

3. Secure hood bottom (E) to the inside of the hood sides
using the supplied #10 x ½ screws.

4. Slide the fresh air filter (H) into the tracks created by
the front of the hood sides and the filter channels.

5. Secure the filter panel (G) to the hood sides. Slide the
filter panel under the front flange of the hood top.

6. Install fresh air hood on ERV.

7. Install barometric exhaust hood over exhaust blower
outlet.

8. Connect field duct connections to duct flanges on back
of ERV. Seal duct connections.

9. Remove ERV control access panel to connect field
wiring.

10. Route class II low voltage wire (3 conductor) from
thermostat or energy management through small
bushing in end panel of ERV. See wiring diagram.

a. Thermostat (dependent) - connect in parallel at

rooftop unit with “G”, “C” and “W”. Then connect
matching color at terminal 1, 2, and 3 respectively
on ERV circuit board.

b. Energy Management - provide +24 VAC to “1” and

common, 24 VAC to “2’ terminals on ERV circuit
board.

c. Thermostat (dedicated) - splice into +24 vac (blue

wire) at (control circuit board) transformer
connection run wire to "R" terminal. Then run
another wire from "G" terminal to ERV (control
circuit board) terminal block #1.

11. All electrical connections must conform to any local
codes and current National Electric Codes (NEC) and
Canadian Electric Codes (CEC). Refer closely to unit
wiring diagram in unit and/or in these instructions for
proper wiring connections.

12. Refer to the unit nameplate for minimum circuit
ampacity (MCA) and maximum overcurrent protection
size (fuse).

13. Electrical data is listed on unit rating plate and motor
name plates.

14. Connect line voltage power supply to ERV fuse block
in control box of unit from disconnect switch. See

wiring diagram.

15. Ground unit with a suitable ground connection either
through unit supply wiring or an earth ground.

Note: Unit voltage entries must be sealed weather

tight after wiring is complete.

16. Remove motor access panels. Locate belts fastened
to blower assembly. Install belt onto motor and blower
pulley. Adjust motor sheave to correct blower RPM for
CFM and external static pressure requirements. See
charts in this instruction. Multiple pulley arrangements
are available to meet the entire range.

(B)

(A)

(G)

(C)

(F)

(D)

(E)

(H)

ASSEMBLED FRESH AIR HOOD

FIGURE 2

Caution: Blower speed must be adjusted for the given

external static pressure and airflow (CFM)
requirements. If blower speed is not adjusted
for conditions, possible motor over loading can
occur.

17. Replace access panel onto the ERV unit and secure.

18. Restore power to unit.

19. Cleanup once unit is operating properly, caulk any
open joints, holes or seams to make the units
completely air and water tight.

20-Leave this instruction manual with owner or in an

envelope to be kept near unit.

VIII - Op er a tion
How It Works

The unit contains an Energy Recovery Wheel (ERW) that
is a new concept in rotary air-to-air heat exchangers.
Designed as a packaged unit for ease of installation and
maintenance, only the connection of electrical power is
required to make the system operational.

When slowly rotating through counter flowing exhaust and
fresh air streams the ERW adsorbs sensible heat and
latent heat from the warmer air stream and transfer this
total energy to the cooler air stream during the second half
of its rotating cycle. Rotating at 50-60 revolutions per
minute, the wheel provides constant flow of energy from
warmer to cooler air stream. The large energy transfer
surface and laminar flow through the wheel causes this
constant flow of recovered energy to represent up to 85%
of the difference in total energy contained within the two air
streams.

Sensible and latent heat are the two components of total
heat. Sensible heat is energy contained in dry air and latent
heat is the energy contained within the moisture of the air.
The latent heat load from the outdoor fresh air on an air
conditioning system can often be two to three times that of
the sensible heat load and in the winter it is a significant
part of a humidification heat load.

During both the summer and winter, the ERW transfers
moisture entirely in the vapor phase. This eliminates wet
surfaces that retain dust and promote fungal growth as well
as the need for a condensate pan and drain to carry water.

PAGE 2

Because it is constantly rotating when in the air stream, the
ERV is always being cleaned by air, first in one direction
then the other. Because it is always dry, dust or other
particles impinging on the surface during one half cycle,
are readily removed during the next half cycle.

During the heating season, when outdoor air temperatures
are below 15oF, it is recommended to use the (optional)
low ambient kit (field installed).

Low Ambient Kit is appropriate for climates with limited
HVAC system operation when outdoor temperatures are
below 10oF.

The frost threshold is the outdoor temperature at which
frost will begin to form on the ERV wheel. For Energy
Recovery Ventilators, the frost threshold is typically below
10oF. Frost threshold is dependent on indoor temperature
and humidify. The table shows how the frost threshold
temperatures vary depending on indoor conditions

FROST THRESH OLD TEM PER A TURE

IN DOOR RH AT 70oF

20% 0oF
30% 5oF
40% 10oF

FROST THRESH OLD

TEM PER A TURE

Because Energy Recovery Ventilators have a low frost
threshold, frost control options are not necessary in many
climates. Where outdoor temperatures may drop below
the frost threshold during the ERV operational hours,
exhaust only frost control option is available.

Low Am bi ent Kit (Op tional)

Low Ambient Kit turns off the supply blower when outdoor
temperatures fall below the frost threshold. The exhaust
only thermostat set points are field adjustable. Supply fan
operation is automatically restored when the exhaust air
temperature rises above the thermostat set point.
Provisions for introducing make-up air into the building
when the supply blower is off to avoid depressurization
should be considered.

Re cov ery Wheel Mode

On a thermostat call for blower operation in heating,
cooling or continuous blower, the ERW will rotate between
fresh air and exhaust air streams. Both the fresh air and
exhaust air blowers will also be operating to overcome the
air resistance of the ERV.

IX - Sys tem Check

1. Disconnect main power.

2. Turn to “Cont” for blower operation on thermostat
controlled models.

3. Restore power to unit. Observe ERV wheel rotation
and both fresh air and exhaust air blowers will
operating.

Note: If Low ambient kit is used the jumper between

TB37-5 & TB37-6 should be removed. Also if
system check out is being conducted at low
ambient temperatures, technician should be
aware that this kit can cause system not to
operate.

4. Verify that the ERV (3) three phase blower motors are
phased sequentially ensuring correct rotation and
operation.

a. Disconnect power.

PAGE 3

b. Reverse any two field power leads to the ERV.

c. Reapply power.

5. Verify that both blower motors are operating under
their full load AMP rating (FLA). The FLA can be found
on each motor and the unit nameplate

A - Re turn Damper Set tings

Manually adjust position of field installed dampers to
balance air flow.

B - Air Flow / Blower Speed Ad just ment

Blower speed selection is accomplished by changing the
sheave setting on both fresh air and exhaust air blowers.
To set ERV for the required air flow (CFM), the external
static pressure applied to the ERV (duct static) must be
known. See the CFM vs External Static Pressure chart for
the appropriate unit to determine the correct blower RPM
for the specified CFM and External Static Pressure.

After blower speed adjustments have been made. Ensure
that when the belt is replaced it is tensioned correctly. The
motor mounting plate can be adjusted to tension the belt. If
using a belt tension checker, adjust the span to the
appropriate setting and check the belt defection force. The
belt deflection force should be between 5-8 lbs or the
lowest tension at which the belt will not slip under peak load
conditions.

5. Disconnect main power to unit before making
adjustment to economizer and/or ERV unit.

6. Replace ERV control access cover.

7. Set thermostat to normal operating position.

8. Restore power to unit.

X - Main te nance

1. All motors use prelubricated sealed bearings; no
further lubrication is necessary.

2. Make visual inspection of motors, belts and wheel
rotating bearings during routine maintenance.

3. Eight pie-shaped segments, are seated on stops
between the segment retainer which pivots on the
wheel rim and secured to the hub and rim of wheel.
Annual inspection of the self cleaning wheel is
recommended. With power disconnected, remove
ERV access panels (rear) and unplug [J150 & P150]

(Refer to wiring diagram in this instruction
manual). Remove segment and wash with water

and/or mild detergent.

4. To install wheel segments follow steps A through E .
See Figure 3. Reverse procedure for segment
removal.

a. Unlock two segment retainers (one on each side of

the selected segment opening.

b. With the embedded stiffener facing the motor side,

insert the nose of the segment between the hub
plates.

c. Holding segment by the two outer corners, press

the segment towards the center of the wheel and
inwards against the spoke flanges. If hand
pressure does not fully seat the segment, insert
the flat tip of a screw driver between the wheel rim
and outer corners of the segment and apply
downward force while guiding the segment into
place.

d. Close and latch each segment retainer under

segment retaining catch.

e. Slowly rotate the wheel 180o. Install the second

segment opposite the first for counterbalance.
Rotate the two installed segments 90o to balance
the wheel while the third segment is installed.
Rotate the wheel 180o again to install the fourth
segment opposite the third. Repeat this sequence
with the remaining four segments.

XI - Pul ley Kit In stal la tion

The units are shipped from the factory at the low static
setting. Pulley kits are available for the medium and high
static settings. To install a pulley kit.

1. Check content of pulley kit, if pulley kit contains:

a. An adjustable sheave and a fixed pitch pulley then

remove belt and both motor and blower pulley

b. An adjustable sheave then remove the motor

pulley.

c. A fixed pitch pulley then remove the blower pulley.

2. Replace pulley(s) with the pulley(s) from pulley kit.
Make sure each pulley is installed with a key. Tighten
the set screw on the pulley(s) to 100 in.lb.

3. Install the belt that came with the pulley kit. Tension
belt as explained in the blower speed adjustment
section.

4. Check the speed of the blower. Adjust the motor
sheave to increase or decrease the speed of the
blower. See blower adjustment section.

WHEEL RIM

E

SPOKE

SEGMENT RETAINER CATCH

D

B

HUB

FIGURE 3

SEGMENT RETAINER

C

SEGMENT

A

D

PAGE 4

Stand Alone ERV’S For Side by Side Duct Arrangements

EXHAUST DUCT FLANGE OPENING

SUPPLY DUCT FLANGE OPENING

Fea tures and Notes

1. Stand alone design allows higher levels of outdoor

air to be introduced into the a/c space.

2. Static test ports provided to verify intake and

exhaust CFM.

3. Balancing damper(s) is field provided when connected

to ductwork. System will not operate properly without
balancing damper.

4. Roof curbs are available for the ERV’s.

5. See blower performance charts for airflow at various

E.S.P..

6. Filter rack with 2” pleated filters included.

K

B

A

F

C

E

J

Roof Curbs (Op tion Codes)

Size 14" 24"

11 CJ51-11 CJ52-11

20 CJ51-20 CJ52-20

28 CJ51-28 CJ52-28

36 CJ51-36 CJ52-36

46 CJ51-46 CJ52-46

62 CJ51-62 CJ52-62

I

H

D

G

D

H

ERV Data Di men sional Data

Size CFM Range A B C D E F G H I J K

11 300-1100 44.75 32.13 33.50 11.00 27.00 4.00 4.25 2.88 2.50 20.75 14.38

20 1200-2000 54.38 37.25 37.50 12.00 30.00 1.63 5.13 4.06 1.63 20.75 17.50

28 1200-2800 52.25 42.62 43.56 14.00 32.00 8.69 5.25 4.25 2.88 20.75 25.50

36 2000-3600 60.00 46.69 57.37 16.50 39.50 12.00 5.50 4.05 5.88 20.75 25.50

46 3000-4600 60.00 52.69 57.37 16.50 39.50 12.00 8.69 5.50 5.88 20.75 28.06

62 4600-6200 72.00 70.88 63.63 19.50 39.50 17.53 14.50 8.70 6.60 20.75 37.75

PAGE 5