Control; Control Of Outdoor Unit - Mitsubishi Electric CITY MULTI PUHY-P200YEM-A Service Handbook

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CONTROL

[1] Control of Outdoor Unit

(1) Initial processing
• When turning on power source, initial processing of microcomputer is given top priority.
• During initial processing, control processing corresponding to operation signal is suspended. The control process-
ing is resumed after initial processing is completed. (Initial processing : Data processing in microcomputer and
initial setting of each LEV opening, requiring approx. 2 minutes at the maximum.)
(2) Control at staring
• For 3 minutes after starting, 60Hz is the upper frequency limit.
(3) Bypass, capacity control
• Solenoid valve consists of bypass solenoid valve (SV1) bypassing between high pressure side and low
pressure side. The following operation will be provided.
1) Bypass solenoid valves SV1 ( "open" when turned on).
Item
When starting compressor
After thermost "ON is returned
and after 3 minutes restart
When compressor stops in
cooling or heating mode
After operation stops
During defrosting operations
During oil recovery opera-
tions
During 30Hz operations, at
fall in low pressure or low
pressure saturation tempera-
ture. (3minutes or more after
starting)
When high pressure rises
(Pd)
When high pressure rises
(Pd) during 30Hz operations
(3 minutes after starting)
Compressor
Bypass
solenoid
valve (SV1)
(4-minute)
ON (Open)
Always turned on or until HPS and LPS is within 0.2MPa.
Turned on for 3 minutes or until HPS and LPS is within 0.2MPa.
Cooling operation normally OFF and heating operation normally ON
when performing oil recovery after continuous operation at low frequency.
Ps is 0.098 MPa or less
When Pd
reaches 2.7MPa or more
When Pd exceed pressure
limit
Start Thermo. Thermo.
OFF ON
(2-minute)
SV1
OFF (Close)
Turned on for 4 minutes
Turned on for 2 minutes
Always turned on
Ps is 0.196 MPa or more
When Pd is 2.35MPa or less 30 seconds
When Pd is less than 1.96 MPa.
Defrost-
ing time
( 1)
(8-minute)
- 54 -
Stop
(3-minute)