Fridgewatch 2100 Controller Mk4
Publication 3-58
Section 3
Page 100 of 152
Issue 1.1 : 01/08
S47 Start variable: select P1 or P2
S47 = 1: P1 used for auto start control.
S47 = 2: P2 used for auto start control.
S48 Stop
variable:
select
P1
or P2
S48 = 1: P1 used for auto stop control.
S48 = 2: P2 used for auto stop control.
S49 Starts per hour (units: 1/hour)
This setting limits the number of starts in any one hour period. This is
done to prevent short cycling, overheating the compressor motor
windings and winding insulation, and reduce wear and tear on the motor
starter switch gear. S49 is initiated each time the compressor starts; if
the compressor is stopped for any reason it cannot restart before the
timed period expires.
The duration of the timed period is derived by dividing 60 minutes by the
starts per hour (S49) value. A typical value for S49 is 4, the default
setting, permitting 1 start every 15 minutes.
It Fridgewatch 2100 is waiting for the starts per hour timer to expire, Wait
S49 SPH Timer appears in the display with a countdown TTS:xxxxs.
S50 Auxiliaries start time (units: second)
Typical auxiliaries are the condenser cooling water pump or evaporator
cooled medium pump.
This is the time in seconds allowed for any auxiliaries to start and provide
a ‘running’ signal to Fridgewatch 2100. If an ‘auxiliaries running’ signal is
not provided before S50 seconds expire, Fridgewatch terminates the start
sequence and displays a trip: event code E30 Auxiliaries Failed to Start.
When a flow switch is used to verify cooling water or cooled medium flow,
S50 can be used to allow sufficient time for flow to become established
and close the flow switch contacts.
S51 Compressor start time (units: second)
This is the time in seconds for the compressor motor to start and provide
a ‘running’ signal to Fridgewatch 2100. If a ‘compressor running’ signal is
not provided before S51 seconds expire, Fridgewatch terminates the start
sequence and displays a trip: event code E9 Compressor Failed to Start.
S52 Oil Differential Pressure Switch (ODPS) delay time
(units: second)
When the compressor starts, and after Fridgewatch 2100 receives the
‘compressor running’ signal, S52 is the time in seconds allowed for the
suction/discharge differential pressure to rise sufficiently to establish oil
flow and close the contacts of oil differential pressure switch ODPS.
If the contacts of ODPS are not closed before S52 seconds expire,
Fridgewatch 2100 terminates the start sequence and displays a trip:
event code E7 Low Oil Differential Pressure (ODP). Establishing a
suitable differential pressure permits completion of the start sequence
and the compressor is displayed as ‘running’.