Scotsman Ice MDT5N25, MDT5N40 service manual Refrigeration Service R-404A HP62

MDT5N25 & MDT5N40

REFRIGERATION SERVICE: R-404A (HP62)

THIS ICE MACHINE USES HP62 REFRIGERANT AND POLYOLESTER COMPRESSOR OIL.

DO NOT USE MINERAL OIL IN THIS REFRIGERATION SYSTEM.

Pressure-Temperature Chart for HP62

VAPORVAPOR

￿R-404A is a “Near Azeotrope”, and therefore	TEMP. PRESSURE
liquid charging is required.	(DEG F)	(PSIG)
Weigh into the discharge side as much as	-20 . . . .	17
possible of the charge as liquid refrigerant.	-18 . . . .	18
Install a sight glass between the manifold	-16 . . . .	20
and the suction side hose. Carefully meter	-14 . . . .	21
liquid refrigerant into the suction side, using	-12 . . . .	23
the manifold valve to “flash off” the liquid	-10 . . . .	24
before it enters the ice machine. Do this until	-8 . . . .	26
the proper charge has been weighed into the	-6 . . . .	28
system.	-4 . . . .	29
￿When the system is serviced, a special liquid	-2 . . . .	31
	0 . . . .	33
line dryer is required.
￿Polyolester oil absorbs water very easily, and	2 . . . .	35
	4 . . . .	37
therefore when the system is opened for
	6 . . . .	39
service, it must be re-sealed as soon as
	8 . . . .	41
possible (15 minutes maximum).
	10 . . . .	43
￿Special leak detection equipment is required to
	12 . . . .	46
locate small refrigerant leaks. Usually a leak	14 . . . .	48
detector capable of detecting a Halogenated	16 . . . .	50
refrigerant or HFC-134A will work. Check with	18 . . . .	53
the leak detector manufacturer if in doubt.	20 . . . .	55
￿As with any other refrigerant, do NOT mix HP62
	22 . . . .	58
with pressurized air when leak testing.	24 . . . .	60
	26 . . . .	63
	28 . . . .	66
	30 . . . .	69
	32 . . . .	72
	34 . . . .	75
	36 . . . .	78
	38 . . . .	81
	40 . . . .	85
	42 . . . .	88
	44 . . . .	91
	46 . . . .	95
	48 . . . .	99
	50 . . . .	102
	52 . . . .	106
	54 . . . .	110
	56 . . . .	114
	58 . . . .	118
	60 . . . .	123
	62 . . . .	127
	64 . . . .	132
	66 . . . .	136
	68 . . . .	141
May 2001
Page 30

TEMP.	PRESSURE
(DEG F)	(PSIG)
70 . .	. . . . 146
72 . .	. . . . 150
74 . .	. . . . 155
76 . .	. . . . 161
78 . .	. . . . 166
80 . .	. . . . 171
82 . .	. . . . 177
84 . .	. . . . 182
86 . .	. . . . 188
88 . .	. . . . 194
90 . .	. . . . 200
92 . .	. . . . 206
94 . .	. . . . 212
96 . .	. . . . 219
98 . .	. . . . 225

100. . . . . 232

102. . . . . 239

104. . . . . 246

106. . . . . 253

108. . . . . 260

110. . . . . 268

112. . . . . 275

114. . . . . 283

116. . . . . 291

118. . . . . 299

120. . . . . 307

122. . . . . 316

124. . . . . 324

126. . . . . 333

128. . . . . 342

130. . . . . 351

132. . . . . 360

134. . . . . 370

136. . . . . 379

138. . . . . 389

140. . . . . 399

142. . . . . 409

144. . . . . 420

146. . . . . 430

148. . . . . 441

150. . . . . 452

152. . . . . 464

154. . . . . 475

156. . . . . 487

158. . . . . 499