Gardner Denver Governor, Manual, Page: 27 / 44

Page 27
13-17-625 v00
Table 4: Delcos Multi-Machine Sequencing Settings
4.5 Delcos Sequencing System Operation
Delcos sequencing systems use a dedicated master running in the Sequencing operating mode.
Up to three slaves can be connected to the master via a serial connection and should be of the
same type of machine (either all fixed speed or all variable speed) and relatively the same
capacity.
Delcos sequencing has the following two functions: (1) a central high-level controller is used to
control a group of compressors in order to maintain the system pressure within a narrow pressure
band, and (2) the master controller regularly changes the priority of the compressors in the group
so that the load is distributed among the compressors.
As long
as the machine’s operating mode is not set to Sequencing, the slaves run independently
of the master and use their local set points. When the sequencing mode is activated, the network
is pressurized within a defined period of time according to the Load Net In setting. To do so, only
the required number of compressors are switched on in order to pressurize the network within this
time period. After a power loss, this function is not activated, because in this case it is important
to pressurize the network as fast as possible.
In case of a Pressure sensor fault on the master controller, the master can no longer control the
group and therefore switches sequencing off until the fault is cleared and reset. If the master
compressor switches itself off because a different fault than the Pressure sensor fault has
occurred, or if it is manually stopped, the master continues to control the sequencing network
using the remaining slaves.
As soon as the pressure is above the Unload Pressure setting, the compressor to the far right in
the sequence is switched off. When the Unload Pressure is exceeded, additional compressors are
switched off in sequence at short time intervals. If the system pressure drops below the Load
Settings Default Values Description
Master Enable Off
Designates which machine in the sequenced network is the Master. Only a single
machine in the network can have Mater Enable turned on. Master Enable must
also set to Off for sequencing with a Connect 12.
Unit Number 1
Number between one and four assigned to each machine in sequence. No two
machines can share a unit number.
Number of
Slaves
0 Number of machines in the sequenced group behind the Master.
Lag Start Delay 15 seconds
The Lag Start delay sets the amount of time Master will wait before asking
another machine to come online.
Load Net In 15 minutes
This value sets the amount of time to increase network pressure to target
pressure from when sequencing is activated. Shorter values will switch on more
compressors at startup. When sequencing is activated, the compressed air
network is filled in the time set and only the number of compressors required to
fill the compressed air network in this time are switched on.
Network Size 5%
Network Size is used to calculate how many compressors to switch on or off to
meet changes in demand. This value should only be changed if there are
significant fluctuations in compressed air requirements. Formula to calculate: a
= (100 x b) / c where a = network size (%), b = network volume size (size of
closest receiving tank, ignore size of pipework and other air tanks), c = total
delivery volume of network.
Transfer Interval 24 hours
The Transfer Interval controls how frequently the sequence is redefined based
on the hours run (BLS) setting of the compressor.