Important – Greenheck MSX (470658) User Manual

Page 20

Modular Supply Make-Up Air Unit

Start-Up - Evaporative Cooling
Recirculating (optional)

1. Check the Installation. The media may have been

removed during
installation, so
its orientation
should be
double
checked. The
media should
be installed with
the steeper ﬂute
angle sloping
down towards
the entering air side.

Verify that the stainless steel caps and distribution
headers are in place. The headers should be located
over the media towards the entering air side. The
caps should be placed over the headers.

2. Check the Pump Filter. Check that the pump ﬁlter

is around the pump inlet.

3. Fill the Sump and Adjust the Float. Turn on the

water supply and allow the sump tank to ﬁll. Adjust
the ﬂoat valve to shut-off the water supply when the
sump is ﬁlled to within 1 inch of the bottom of the
overﬂow.

4. Break-In the Media. Open the bleed-off valve

completely and saturate the media with the blower(s)
off for no less than 20 minutes.

5. Check the Flow Rate. The pumps should provide

enough water to saturate the media in 45 to 60
seconds. Consult the factory, if adequate ﬂow is not
achieved.

6. Adjust the Water Bleed-Off Rate. The water

bleed-off rate is dependent on the water’s mineral
content. The bleed-off should be adjusted based
on the media’s mineral deposits after two weeks of
service.

7. Set the Optional Auto Drain and Fill. This system

will automatically drain the sump tank and ﬁll it
with fresh water at the ﬁeld-adjustable intervals,
typically once every 24 hours. This ﬂushes mineral
build-up and debris from the tank to promote low
maintenance and increase media pad life.

In addition, the system will protect the evaporative
cooler from freezing by draining the sump tank and
supply line when the outside temperatures fall below
the set point of the outside air sensor. Typically, this
is set at 45º to 50º F. The auto drain and ﬁll outdoor

Bleed-Off

Valve

Overflow

Pump

Filter

Threaded Float

Adjustment

Supply

Connection

Float

Valve

IMPORTANT

Check the media for minerals after two weeks of
service and adjust the bleed-off rate accordingly.

Leaving Air

Entering Air

45º

15º

Media Orientation

Evaporative Cooler Set-Up

NOTE

A jumper will need to be installed in the control center
to power the evaporative pumps with the blower(s)
off. Reference the unit’s ladder diagram to determine
proper terminals.

air sensor should be installed in an area that is
shaded from direct sunlight so the outside air sensor
probe will detect an accurate air temperature.

Set the Timer Scale and
Settings dials:

•

T1 timer setting set to 10
and timer scale set to 1d
for 1 day of operation

•

T2 timer setting set to 10
and the timer scale set
to 10m for 10 minutes of
drain time

8. Put the Unit into Service.

Remove the jumper, and
energize the blower(s). Verify
proper operation.

Timer
Scale

Timer

Settings