Electra DCI 72, Service Manual

Page: 60 / 105

12-10
CONTROL SYSTEM
SM WNGDCI 2-E.4 GB
12.7.5.2 Heat Sink Overheating Protection For DCI 72 / 80
HST
Delta HST
<-2 -2 -1,0,1 2 >2
HST ≥ 81 SC SC SC SC SC
79 ≤ HST < 81 D1 D1 D2 D2 D2
75 ≤ HST < 79 SR SR D1 D2 D2
73 ≤ HST< 75 SR SR SR D1 D1
71 ≤ HST ≤ 73 Norm Norm Norm SR SR
HST < 71 Norm
12.7.6 System Over Power Protection Only For DCI 72 / 80
Power
Delta PWR
< -2000 [-2000,0) 0 (0,2000] > 2000
PWR1 PWR2
PWR ≥ 3500 PWR ≥ 2900 SC SC SC SC SC
3300 ≤PWR < 3500 2750 ≤PWR < 2900 D1 D1 D2 D2 D2
3100 ≤PWR < 3300 2600 ≤PWR < 2750 SR SR D1 D2 D2
3000 ≤PWR < 3100 2450 ≤PWR < 2600 SR SR SR D1 D1
2950 ≤PWR ≤ 3000
2300 ≤PWR ≤
2450
Norm Norm Norm SR SR
PWR < 2950 PWR < 2300 Norm
There are two sets of OVRPWR values, the selection of the values are set according to the state of
the Power-Shed input.
Power-Shed input open Set values 1
Power-Shed input sort Set values 2
12.7.7 Outdoor Coil Deicing Protection
12.7.7.1 Outdoor coil Deicing Protection For DCI 50 / 60 / 72Z
►
Entering Deicing Conditions
Deicing operation will start when either one of the following conditions exist:
Case 1: OCT < OAT – 8 AND TLD > DI
Case 2: OCT < OAT – 12 AND TLD > 30 minutes.
Case 3: OCT is Invalid AND TLD > DI
Case 4: Unit is just switched to STBY AND OCT < OAT – 8
Case 5: NLOAD = 0 AND OCT < OAT -8
Case 6: OCT<-
19 AND TLD> 60 minutes
All this condition will exist during 10 seconds
OCT – Outdoor Coil Temperature
OAT – Outdoor Air Temperature
TLD – Time from Last Deicing
DI – Deicing Interval (Time Interval Between Two Deicing)
Deicing interval time when compressor is first started in heat mode, is 10 minutes if OCT < -2, and
is 40 minutes in other cases.
Deicing interval time is changed (increased/ decreased in 10 minutes steps) as a function of deicing
time. If deicing time is shorter then former deicing time, the deicing interval time will be increased. If
deicing time is longer then former deicing time, the deicing interval time will be decreased.
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