Low Am bi ent Kit
Low Ambient Kit turns off the supply blower when outdoor
temperatures fall below the frost threshold. Exhaust Only
set points are field adjustable with a factory supplied
thermostat. 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 ERV media will rotate
between fresh air and exhaust air streams. Both the fresh
air blower and exhaust air blower will be operating to
overcome the air resistance of the ERV media. The ERV
unit will operate in this mode until economizer mode is
activated.
Econo mizer/Power Ex haust Mode
On the activation of the economizer mode [closure of
damper switch], the ERV unit will shutdown for
approximately 60 seconds to allow the ERV media to pivot
out of the air stream. After the delay timer has been
satisfied, the exhaust air blower will operate. The ERV unit
will act as a power exhaust unit.
This mode will continue until economizer has been
deactivated. The exhaust air blower will shut down and the
delay timer will be activated. During this time period the
ERV media will pivot back into the air stream. When timing
is complete the unit will operate in the Recovery Wheel
Mode.
IX - SYS TEM CHECK
1.
Disconnect ERV main power.
2.
Remove ERV control access panel and install jumper
at low voltage terminal strip between "TB37-1 and
TB37-2". Wheel should pivot out of air stream.
Note - If optional 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.
3.
Turn thermostat to "Cont" for blower operation.
4.
Restore power to unit. Observe ERV drive motors
(damper motor) for wheel and dampers, it should pivot
wheel out of air stream, opening fresh air dampers and
a delayed exhaust blower will operate.
5.
Remove jumper(s) from low voltage terminal block
(TB37). View pivoting of media back into air stream
and closing of fresh air dampers. After delay timer has
cycled then both fresh air blower and one exhaust air
blower will operate.
6.
Disconnect main power to unit before making
adjustment to economizer and/or ERV unit.
7.
Replace ERV control access panel.
8.
Set thermostat to normal operating position.
9.
Restore power to unit.
PAGE 4
A - Economizer Set tings
Refer to economizer instructions for minimum air flow
requirement. The damper end switch setting on the
internal economizer damper assembly is field adjustable to
any position above minimum air flow for fresh air
requirements at the customers specified conditions.
B - Blower Speed Ad just ment
Blower speed selection is accomplished by changing the
sheave setting on both fresh air and exhaust air blowers.
Both blowers are factory set at "closed" for maximum
airflow. To determine air flow setting, external static
pressure readings will need to be read across the ERV.
See Figure 4
for location to take pressure readings.
1.
Disconnect main power to unit before making
adjustment to economizer and/or ERV unit.
2.
Replace ERV control access cover.
3.
Set thermostat to normal operating position.
4.
Restore power to unit.
Figure 4
C - Air Bal anc ing Ad just ment
1.
Remove plastic plugs in door panels (4 total).
2.
With a manometer measure pressure drop [inches of
water column] across top half of ERV (top holes in door
panel). Unit CFM is determined then by referring to
Table #1
. If CFM values are not per design, adjust
damper in fresh air hood and repeat measure method.
3.
Repeat the same process for the bottom half of ERV. If
CFM values are not per design, adjust internal
dampers inside the ERV . This is accomplished by
removing door panel at the return air opening, loosing
screw in center of damper, then slide damper rod up or
down in the return airstream and re-tighten screw.
Replace door panel and repeat measurement method.
4.
Place plastic plugs back in to door panels.
