hussmann GSVM - Manual (Page 13)

13
Be sure that all s ervice valves are open to al-
low all of the mixture to be discharged.
b. Connect a deep-drain vacuum pump to
both the high and l ow side of the system.
Pull a vacuum on the system to at least
15 00 microns.
c. Break the vacuum by adding refrigerant
into the system until the pressure is above
0 psig. Always charge the refrigerant line
into the system through a new drier in the
charging manifold line. A 16 cubic inch
drier is sufficient for this purpose.
d. Repeat steps 2 and 3 two more times, the
third time evacuating the system to 500
microns.
The following pressures are optimum
when the cas e in a 75º to 80ºF ambient and is
running from 35º to 40ºF cabinet tempera-
ture and are for reference only:
MODEL NO. REFRIGERANT SUCTION PRESSURE HEAD PRESSURE
TYPE (psig) (psig)
GSVM4060 R-134a 12-15 130-150
GSVM4072 R-134a 12-15 130-150
GSVM5272 R-134a 14-18 130-150
GSVM5272 R-404A 40-50 310-320
Consult the serial plate for the correct refrigerant charge. This charge is critical and
should be weighed in.
TEMPERATURE CONTROL –
The temperature control is located in
the electrical box. The sensing bulb is lo-
cated on the left hand end of the lower back
wall.
When replacing make s ure the bulb
is in the proper location and that the hole in
the liner is properly sealed after the replace-
ment has been made.
The control is adjustable from –30º to 50ºF
(dial face marking). The actual cabinet tem-
perature is approximately 6 to 9º warmer
than the control setting so this must be
taken into consideration.
The control also has an adjustable differen-
tial that determines the difference between
the cut-in and cut-out temperature. This is
adjustable from 5 to 20º. The factory set-
ting is from 8-10º to insure proper off time
to keep the evaporator from icing.
EVAPORATOR F AN MOTORS –
To replace an evaporator fan motor,
the product must be removed from the
cabinet and the bottom shelf also removed.
Next, remove the plate covering the
fans by removing the 2 screws, and 4 bolts
holding this in place. The fans are now ac-