Suction Pressure High; Oil Differential Pressure Low At Start-Up; Fig 64 Suction Pressure Low: Settings Alt2, Alt3, Alt7, Alt8 And Altt2 - J&E Hall Fridgewatch 4000 Installation, Operating And Maintenance Manual

Fridgewatch 4000 Controller Mk2
ALT2 Suction pressure
ALT3 Suction pressure
ALT7 Suction pressure
ALT8 Suction pressure

Fig 64 Suction Pressure Low: Settings ALT2, ALT3, ALT7, ALT8 and ALTT2

17.9.4.
17.9.5.
Section 3
Issue 3.3 : 01/23
Suction Pressure
low: load inhibit
low: force unload
low alarm
low trip
ALTT2 times out. FW4000 displays 'Suction Pressure Low Alarm'
FW4000 stops the compressor and displays 'Suction Pressure Low Trip'

Suction Pressure High

Transmitter wired to ANIN 1, used to sense suction pressure.
ALT4 Suction pressure high: load inhibit (units: bar g)
ALT5 Suction pressure high: force unload (units: bar g)
ALT6 Suction pressure high alarm (units: bar g)
ALTT1 Suction pressure high alarm delay time (units: second)
ALT4 defines the suction pressure limit above which compressor loading
is inhibited, ALT5 defines the limit above which FW4000 sends
continuous unload pulses until suction pressure falls below the ALT5
limit. These limits override the output from the P + I algorithm or external
load/unload signals.
NOTE: The value assigned to ALT4 Load Inhibit must
normally be < than ALT5 Force Unload.
If suction pressure rises to the ALT6 alarm value, time delay ALTT1 is
initiated. FW4000 displays 'Suction Pressure High Alarm' if suction
pressure is above the ALT6 value when ALTT1 times out. ALT6 would
normally be set above the ALT5 force unload pressure value.

Oil Differential Pressure Low at Start-up

ALT13 Oil differential pressure at start-up (ODP2) low trip
(units: bar)
ALTT4 Oil differential pressure at start-up (ODP2) delay time
(units: second)
The method of oil pressure sensing at start-up is defined by SC7 Oil
Differential Pressure at Start-up (ODP2) Sensing Defined.
Time delay ALTT2 initiated
Time →
Publication 3-71
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