Greenheck DG/DGX Pilot Ignition (470651_IOM) - Manual (Page 13)

7. Evacuate and Charge the Coil
Use a vacuum pump to evacuate the coil and any
interconnecting piping that has been open to the
atmosphere. Measure the vacuum in the piping using
a micron gauge located as far from the pump as
possible. Evacuate the coil to 500 microns or less,
and then close the valve between the pump and the
system. If the vacuum holds to 500 microns or less
for one minute, the system is ready to be charged or
refrigerant in another portion of the system can be
opened to the coil. A steady rise in microns would
indicate that moisture is still present and that the coil
should be further evacuated until the moisture has
been removed.
8. Install the Drain Line
Connect an
unobstructed drain
line to the drain
pan. A trap should
be used to prevent
sewer gas from being
drawn into the unit.
NOTE
Failure to obtain a high vacuum indicates a great
deal of moisture or a small leak. Break the vacuum
with a charge of dry nitrogen or other suitable
gas and recheck for leaks. If no leaks are found,
continue vacuuming the coil until the desired
vacuum is reached.
IMPORTANT
All traps must be installed below the roof line or be
otherwise protected from freezing.
6 in. min.
6 in. min.
Drain
Trap
6 in. min.
6 in. min.
Drain
Trap
Installation of Chilled Water Coil
Piping (optional)
1. Verify Coil Hand Designation
Check the coil hand
designation to ensure that
it matches the system.
Coils are generally plumbed
with the supply connection
located on the bottom
of the leaving air-side of
the coil and the return
connection at the top of the entering air-side of the
coil. This arrangement provides a counter flow heat
exchanger and positive coil drainage.
2. Check the Coil for Leaks
Pressurize the coil to 100 psig with dry nitrogen or
other suitable gas. The coil should be left pressurized
for a minimum of 10 minutes. If the coil holds the
pressure, the hook-up can be considered leak free.
If the pressure drops by 5 psig or less, re-pressurize
the coil and wait another 10 minutes. If the pressure
drops again, there is likely one or more small leaks
which should be located and repaired. Pressure losses
greater than 5 psig indicate a large leak that should be
isolated and repaired.
3. Connect the Supply & Return Lines
Connect the supply and return lines as shown above.
4. Install the Drain Line
Connect an unobstructed
drain line to the drain pan.
A trap should be installed
to prevent sewer gas from
being drawn into the unit.
Hot Return
Connection
Cold Supply
Connection
Entering
Air Leaving
Air
IMPORTANT
Guidelines for the installation of the cooling coil
have been provided to ensure proper performance
of the coils and their longevity. These are general
guidelines that may have to be tailored to meet the
specific requirements of any one job. As always,
a qualified party or individual should perform the
installation and maintenance of the coil. Appropriate
protective equipment is recommended during the
installation and maintenance of the coil.
When installing couplings, do not apply undue
stress to the connection. Use a backup pipe
wrench to avoid breaking the weld between the coil
connection and the header.
All field-piping must be self-supporting. System
piping should be flexible enough to allow for the
thermal expansion and contraction of the coil.
IMPORTANT
All traps must be installed below the roof line or be
otherwise protected from freezing.
Model DG / DGX Pilot Ignition Make-Up Air 13
®