Danfoss VZH052 Manual page 34

Manage operating envelope
Test N° Purpose
Check reaction
1 of system to oil
boost
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Multiple envelope control: Speed range <2400 allowed
Controller needs to manage speed limitation
according to operating conditions.
1000RPM to 1800RPM is allowed in area 1.1
1800RPM to 2400RPM is allowed in area 1.1 and
1.2
Protection required
• HP switch*
• LP switch*
• DGT set @ 135°C (275°F) if necessary
see §Discharge T° protection
•Measurements of suction and discharge pressure,
unit controller is permanently maintaining compressor
within its envelope with right minimum speed
•drive setting:
parameter 4-11[ Motor speed low limit(rpm)]: keep
default value as 1000
*for more details see "Control Logic"
Test condition
Stabilized the system in area below
minimum speed (2400RPM) until oil
boost happen
2400RPM to 6000RPM is allowed in area 1.1; 1.2
and 1.3
4200RPM to 6000RPM is allowed in all area
Below 2400RPM oil boost function is enabled by
default (more details "Oil management logic")
See "Test, criteria and solutions"
Condensing pressure control
Perform oil boost test 1 described below
Pass criteria
No unsafties happen
Superheat requirement fullfilled
HP switch
2400-6000rpm
1800-6600rpm
1000-6600rpm
Solutions
Modify ramp-up
Modify superheat control