Daikin MicroTech III DPS Installation And Maintenance Manual page 53

Table 36: Alternate Initialization Sequence, 3–15 Tons
Device
Inverter Compressor & Comp3
Inverter Compressor Only
Outdoor Fan
4 Way Valve (Heat Pump)
Outdoor Coil
Expansion Valve (EVO)
(Heat Pump only)
SVR (Heat Pump only)
SVB
Indoor Coil
Expansion Valve (EVI)
Time Duration
A . Inverter compressor speed is increased until the 4-way valve is seated (discharge minus suction pressure >57 psi) and as
long as the suction pressure is above 43 psi . inverter compressor speed is also increased if the suction pressure remains
above 71 psi . Comp 3 turns on if the inverter compressor speed is at maximum and these conditions are not met . Comp 3
is turned back OFF after 20 seconds if the suction pressure drops below 43 psi .
B . Outdoor fan capacity is controlled to maintain the discharge pressure between 171 psi and 221 psi . Outdoor fan capacity
is set to 100% if discharge pressure is above 427 psi . Outdoor fan capacity runs at least at minimum capacity if inverter
board (fin) temperature >167°F.
C . EVI is controlled to keep the suction superheat between 3 .6°F and 14 .4°F .
D . Alternate Initialization lasts a maximum 15 minutes. It is completed early anywhere between 10 seconds and 15 minutes if
once the 4-way valve is seated (differential pressure above 57 psi and the discharge superheat above 9.0°F).
E . Step 3 ends when the compressor has reached 65% full speed, differential pressure is >26 psi for 3 seconds, the stage
has been active for 3 minutes, or Comp3 is active
F . Step 4 (initializaiton) is complete when the stage has been active for 15 minutes, or 4 way valve has set and discharge
superheat is above 9°F
www .DaikinApplied .com
Step 1
Inverter Compressor Speed =
Inverter Compressor Speed =
Smaller of Step 12 or Maximum
Minimum Comp3 = Off
If OAT ≥50°F or RAT ≥73°F,
Inverter Compressor Speed =
Inverter Compressor Speed = Smaller of Step 12 or Maximum
Minimum If OAT <50°F or RAT <73°F,
Inverter Compressor Speed =
Outdoor Fan = 0% if OAT <
68°F
Outdoor Fan = 5% if OAT ≥
68°F
OFF
EVO = 100%
Closed
Normally Open
Close if Discharge superheat
>9°F
EVI = 0%
5 Seconds
Step 2
Comp3 = Off
Minimum"
B
←
←
←
←
C
E = 15 Ton size
5 Seconds
D ≠ 15 Ton size
53 OM 1263 • MICROTECH UNIT CONTROLLER
Operator's Guide
Step 3 Step 4
←
←
←
←
←
←
←
←
F= 15 Ton size
A
A
←
←
←
←
NA
←
NA