SYSTEMS
blower | compressor | vacuum
Item
Correct MOV
algorithm
MCP
modulation
commands
Advanced
Parallel
Control
Step
sequence
Lead / lag
assignment
Loop locking
Main Header
Blow Off
Valve Timing
SCOPE OF WORK CONTROLS -— Nashua WTF
Description
Update MCP program to use Flow control
with MOV as primary control method.
Update MCP program to use pulsed
increase / decrease commands to online
blowers.
Update MCP program to use advanced
parallel control as modulation control
method. Advanced parallel control allows
individual control of online blowers while
maintaining similar output levels.
Update MCP program to modify step
sequence so the lag one blower is only
started when the lead blower has reached
maximum output and more air is required.
Program currently starts countdown to start
lag blower when lead blower is at max even
if no more air is required for process.
Update MCP program to change how lead
and lag blowers are selected. Current
program assigns lead lag position based on
pressing the Lead button or by how blowers
are put into Local / Remote modes.
Update MCP program to prevent any basin
valve from modulating when a lead or lag
blower is coming online.
Update MCP programs to use percent per
second timers for opening and closing main
header blow off valve.
Purpose
e Prevent system from “hunting”
Lower header pressure which
will reduce power consumption.
e Easier to match system
demand with blower output
using flow control.
e Prevent system from
undershooting and then
overshooting when modulating
blower output.
e Reduce electrical and
mechanical stress on actuators
e Reduce stress on lead blower
when two blowers online.
Increase system air flow ata
given header pressure.
Prevent fag blower [rom turning
on unnecessarily and then
causing blowers to cycle.
In the interest of safety, a blower
should not be allowed to be put
into remote mode from a remote
source when it has been placed in
local mode at the blower’s control
panel.
Increase system stability by
maintaining valve position while
blowers are starting.
Create more predictable control of
blow off valve movement.
