Refrigerating Specialties Division 2
MANUAL OPENING STEM
The manual opening stem on the Type S81 is for the
purpose of opening the valve without energizing the
solenoid coil. Refer to the exploded view and the parts
list for location of the stem and other related parts. For
access to the stem, the seal cap must be removed.
This must be done with caution as refrigerant may be
trapped inside the seal cap. Manual opening is ac-
complished by turning the stem counter clockwise until
stopped. To reset for automatic operation, turn the stem
clockwise until seated.
INSTALLATION
The solenoid valve can be mounted in a hori-
zontal or vertical line with the flow in the direction of the
arrow on the valve body. Protect the inside of the sole-
noid valve from moisture, dirt and chips during installa-
tion. These valves may be soldered into the line without
disassembly. A wet cloth should be wrapped around the
valve and the soldering flame should be directed away
from the valve body. The S81 solenoid valve must be
installed with the arrow on the valve body in the direc-
tion of flow through the valve. If the valve is backwards,
the flow will not be stopped when the valve is electrically
de-energized. Like all Solenoid Valves, the S81can stop
flow only in the direction from normal inlet to normal
outlet (as shown by the arrow on the body). If reversal
of pressure occurs in the system so the outlet pressure
exceeds the inlet pressure the plug will be blown away
from its seat and reverse flow will occur. If a system has
this type of pressure reversal, a Refrigerating Special-
ties Division Type CK4A check valve, in series with the
solenoid valve, will prevent reverse flow. (The CK4A
must be installed downstream of the solenoid to avoid
trapping liquid.)
ELECTRICAL
The Refrigerating Specialties Division
molded water resistant Class “H” solenoid coil is
designed for long life and powerful opening force.
The standard coil housing meets NEMA 3R and4
requirements. This sealed construction can with-
stand direct contact with moisture and ice. By
definition, Class “H” coil construction will permit coil
temperatures, as measured by resistance method,
as high as 185°C (366°F). Final coil temperatures
are a function of both liquid and ambient tem-
peratures. The higher fluid temperatures require
lower ambient temperatures so the maximum coil
temperature is not exceeded. Conversely, low flu-
id temperatures permit high ambient temperatures.
A solenoid coil should never be energized except
when mounted on its corresponding solenoid tube.
The molded Class “H” coil is available from stock
with most standard voltages. However, are avail
avail ble for other voltages and frequencies, as
well as direct current. Coils are also available as
transformer type with a 6 volt secondary winding
for use with the Refrigerating Specialties Division
Pilot Light Assembly PLT2. See Bulletin No. 60-20.
The solenoid coil must be connected
to electrical line with volts and Hertz same as
stamped on coil. The supply circuits must be prop-
erly sized to give adequate voltage at the coil leads
when other electrical equipment is operating. The
coil is designed to operate with line voltage from
85% to 110% of rated coil voltage. Operating with
a coil voltage above or below these limits may
result in coil burnout. Also, operating with a coil
voltage below the limit will definitely result in lower-
ing the valve’s maximum opening pressure differ-
ential. Power consumption during normal operation
will be 10.2 watts or less.
SERVICE POINTERS
1. Failure to Open: (a) Coil is of incorrectly high
voltage. See “Electrical”. Check voltage printed on
the coil. (b) Line voltage is abnormally low. See
“Electrical”. Check line voltage at coil leads with a
voltmeter. (c) Failure to electrically energize. Check
control circuit. (d) Pressure difference across valve
is too high. The S81 and S82 will open against a
maximum pressure difference across the valve of
21 bar (300 psig). (e) Solenoid
Coil is burned out. See “Electrical”, and replace
with proper coil. (f) Plunger Assembly is stick-
ing. To disassemble the S81for inspection of
internal parts (after pumping out the system as
required); disconnect power source to Solenoid
Coil, remove(number 36) Solenoid Operator As-
sembly, then Adapter. Remove every trace of dirt
from Adapter and Cartridge Assembly. Thoroughly
clean all parts and reassemble using alight film
of refrigerant oil. 2. Failure to Close: (a) Electrical
control circuit is not opening properly. Check wiring
and controls. (b) There are chips or dirt on the Pilot
Seat or the Piston Plug Seat, preventing proper
seating. Disassemble and clean Valve as outlined
in 1 (f) above.(c) Piston Plug Seat or Pilot Seat
may be worn or damaged and therefore leaking.
Disassemble and clean Valve as outlined in 1 (f)
above. If any of these parts need replacing, it is
advisable to replace using the proper replacement kit.
(d) Manual Opening Stem is turned all or partly out and
permitting flow through the valve. 3. Leakage Through
Valve: See (2) above
