Section 7 • Timers Overview; Timer Setpoints - Emerson VILTER MicroVission Operation And Service Manual

Section 7• Timers
Overview
The Timers screen allows the operator to view and adjust
timer settings associated with the compressor opera-
tion. There are different types of timers that the opera-
tor should be aware of listed below. For Timers Screen
pages, see Figures 7-1 & 7-2.
Changeover
The changeover timers will change from one type con-
trol to another once the compressor has started and
then the time has expired.
Bypass
The bypass timers prevent certain alarm and trip checks
from occurring until the compressor has started and
then the time has expired.
Delays
The delay timers require the condition to occur for the
specified amount of time.
Timers
A general timer requiring the time to be expire before
the listed event can occur.
MicroVission Controller • Operation and Service Manual • Emerson • 35391MV 1.3

Timer Setpoints

Following are the setpoints that the operator can config-
ure on MicroVission.
Load Increase Start Delay
At compressor startup, the compressor capacity will be
at minimum load for this time. This is to allow compres-
sor and system conditions to stabilize. After this timer
expires, the system modulates the compressor capacity
according to the system demands.
Compressor Interlock Bypass
Once the MicroVission has sent a command to the com-
pressor starter to start, it expects the return signal. This
timer defines how much time to wait for that signal be-
fore setting a trip condition.
Low Oil Pressure Diff. Bypass
This is the time for which the "Low Oil Pressure" safety
setpoints will remain inactive. After the timer has ex-
pired, the "Low Oil Pressure" safety setpoints will be-
come active and safeties related to "Low Oil Pressure"
will get monitored.
Figure 7-1. Timers Screen (Page 1)
7 – 1