Separate Correction; Lev Opening Correction By Discharge Temperature - Mitsubishi Electric MSH09TW Service Manual

(2) Separate correction (COOL, DRY)
(Correction is performed only for operating unit.)
(When 2 or more units are operating.)
Correction by the separate super heat.
Correct the LEV separately by the difference between gas pipe temperature and minimum gas pipe temperature.
1 Calculate super heat using the expression below.
(Super heat) = (Each gas pipe temperature) - (Minimum gas pipe temperature)
2 Separate correction is performed according to each super heat in the table below.
Difference of
superheat
more than 48.2
42.8 to 48.2
37.4 to 42.8
37.4 or less

(3) LEV opening correction by discharge temperature

When LEV correction output is 0 pulse by the suction super heat at COOL, DRY or HEAT operation, correct LEV is
corrected according to the following table.
The target discharge temperature is determined according to frequency zone and number of operation unit of the
compressor.
Operation frequency
of compressor
Minimum ~ 20
21 ~ 30
31 ~ 40
41 ~ 55
56 ~ 70
71 ~ 90
91 ~ maximum
Correct the LEV opening according to difference between the target discharge temperature and discharge temperature.
more than Target discharge temperature+19.8
Target discharge temperature+19.8 to Target discharge temperature+14.4
Target discharge temperature+14.4 to Target discharge temperature+9
Target discharge temperature+9
Target discharge temperature+3.6 to Target discharge temperature-3.6
Target discharge temperature-3.6
Target discharge temperature-9
Target discharge temperature-14.4 to Target discharge temperature-19.8
Target discharge temperature-19.8 or less
LEV opening
correction (pulse)
8
6
2
0
COOL, DRY
Number of operating unit.
Single Double
123.8 140.0
134.6 147.2
149.0 154.4
152.6 161.6
158.0 170.6
161.6 181.4
165.2 183.2
Discharge temperature (°F)
to Target discharge temperature+3.6
to Target discharge temperature-9
to Target discharge temperature-14.4
HEAT
Number of operating unit.
Triple Single Double
143.6 131.0 120.2
150.8 136.4 125.6
163.4 145.4 131.0
174.2 158.0 136.4
186.8 176.0 145.4
194.0 185.0 156.2
194.0 185.0 165.2
69
Triple
118.4
123.8
129.2
134.6
143.6
154.4
163.4
LEV correction
opening (pulse)
COOL HEAT
10 7
4 6
2 3
1 2
0 0
-1 -1
-2 -1
-5 -3
-8 -7