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(continued) Page 6
DEHYDRATION OF
REFRIGERATION
SYSTEM: 2 . To prevent scaiing due to brazing, dry nitrogen should be
allowed to flow through lines while brazing operations are
taking place.
3 . After installation is complete and checked for leaks, pump
a deep vacuum using a vacuum pump. DO NOT USE THE CONDENSING
UNIT FOR THIS PURPOSE.
4 . Break vacuum on system by releasing refrigerant through a
dehydrator until pressure gauge reads above zero pounds.
Repeat steps three and four.
5 . A dehydrator should be used in the charging line when adding
refrigerant.
6 . A dehydrator of sufficient capacity must be installed in the
liquid line before placing system into operation.
DEFROSTING: This Warren/Sherer meat merchandiser (Ml) has "AIR DEFROST'*
as standard. The evaporator fans run continuously during
the refrigeration cycle. These same fans reverse during the
defrost cycle, which is initiated by the time clock. The
time clock (normally open circuit) energizes the relay at the
case, which reverses the fans and pulls store air into the
honeycomb at the refrigeration outlet and thru the air ducts,
evaporator coil, and discharges the air out the return grills.
One (1) thermo-disc located on the evaporator coil terminates
the defrost cycle. The thermo-disc is non-adjustable and
are set O 45oF. The thermo-disc is located at the bottom right-
hand of the evaporator coil. It is necessary to remove the
valve access plate on fan housing td see or service this control.
The time clock should be set @ a failsafe setting of 45
minutes and for three (3) defrost per day (every 8 hours).
When high humidity exists, it may be necessary to increase
to four per day (every 6 hours).
DEFROST CONTROLS: ' ihe defrost is initiated by atime clock at the condensing
unit control panel which energizes the relay at the case to
b 4. 'a reverse the fans.
; ?...ks'I A 208/230 volt control circuit from time
, ,.,I\ r;:;
(, <J .& b,**::L., .,k, p- -' clock to the relay @ the case is required. Defrost is ter-
\ J'9gf.J' 2 ..).d
s . i -g.* /-$.<>a.
.Qi'~ ,-*,.y'$
-> minated by the therm-o-disc (45O) attached to the evaporator
<.'
f-J-+ ,~~,.~,~~~..c-c- coil. Control wiring from the therm-o-disc to time clock should
.,':‘r 6%
*I*
** d be wired as shown on the wiring diagram.
* %
HiT.;GAS DEFROST
(ACCESSORY): Reverse cycle defrost kits are offered as an accessory
and are installed at the factory. Reverse cycle hot gas
defrost is not recommended above air defrost but may be
specified when using Dual-Metic type condensing units.
Control settings are the same as for air defrost.
