Greenheck DG / DGX with Direct Spark (470652) - Manual (Page 13)

Direct Spark Ignition Make-Up Air 13
®
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
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. Protective
equipment such as safety glasses, steel toe boots and
gloves are 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.
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
vacuumed until the moisture has been removed.
6 in. min.
6 in. min.