7.9 REMOTE LOAD/UNLOAD
The remote load/unload option gives the operator the
ability to control the loading and unloading of the
compressor. This option is enabled when two switches
are wired to the Intellisys to perfor m this function.
The firstswitch is the master/local input (P3, 25 & 26)
and the second switch is the load/unload input (P3,
27 & 28). If the master/local switch is closed, the
Intellisys will read the load/unload switch for loading
and unloading the compressor. If the load/unload switch
is closed, the Intellisys will load the compressor.
If the load/unload switch is open, the Intellisys will
unload the compressor. If the master/local switch is
open, the Intellisys will ignore the load/unload switch
and operate the compressor normally.
7.10 MODBUS
The Modbus option uses the Modbus protocol and
modbus address set points in the OPTIONS menu. This
is used by the Ingersoll-Rand service organization.
7.11 INTEGRAL SEQUENCING
Integral sequencing allows one compressor, the lead, to
sequence up to 3 other compressors.The compressors
are daisy chained together using por t P8 on the Intellisys.
Each compressor has a unique address and the lead
compressor will sequence the other units in numerical
order based on that address.
The lead compressor will be the first to load and the last
to unload. It is also the only compressor that can
modulate. If the lead compressor’s mode of operation is
Mod/ACS or Modulation Only, it will modulate when it is
loaded. Once loaded, if pressure falls to its online set
point, the lead compressor will transmit a load command
to the next compressor in sequence. The lead compressor
will then wait for a period of time for the line pressure to
rise. This time per iod is deter mined by the load delay time
set point. At the end of this time period, if line pressure is
not rising, the lead compressor will transmit a load
command to the next compressor in sequence. This will
be repeated until the line pressure star ts to r ise.
When line pressure rises to the lead compressor’s offline
set point, it will transmit an unload command to the last
loaded compressor in the sequence.The lead compressor
will do this every 10 seconds until the line pressure starts
to fall.
After a cer tain amount of time or at a certain time, the
lead compressor can change the sequence by transferring
the lead to the next compressor in the sequence. If the set
point, Lead Change - Hours, is set to a value greater than
0, the unit will operate as the lead compressor for that
number of hours before transferring the lead. If Lead
Change - Hours is set to 0, the set points Lead Change -
Day and Lead Change - Time will be used to deter mine
when the lead will be transferred. The Lead Change - Day
set point will contain the day of the week the lead will be
transferred. The time of the day will be contained in the
Lead Change - Time set point. The lead will be transferred
when the real time clock matches these 2 set points.
To connect the compressors for integral sequencing put
the 4 position connector into por t P8. One connector, I-R
par t number 39186101, will be needed for each
compressor. The total length of cable for an integral
sequencing system is not to exceed 1000 feet. For the
cable, use I-R part number 39204508 or equivalent. This
is a 4 wire, twisted pair cable. Use one pair for pins 1 and
2 and the other pair for pins 3 and 4. The connection on
por t P8 is a one to one connection. The wire on pin 1 on
the first compressor will connect to pin 1 on the second
compressor and so on. This is tr ue for all 4 wires.
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