FORM 195.26-NM3
YORK INTERNATIONAL
45
C. Timer Operation at Pressures
“Below the Control Zone” (Fig. 18)
FIG. 18 – “ABOVE THE CONTROL ZONE”
Loading Timer:
This 150 sec. timer constantly cycles
from 150 sec. to “0” and restarts at
150 whenever the unloading timer
starts at 30 sec. as long as sucton
pressure stays “Below the Control
Zone”. No loading action will take
place while pressure is “Below the
Control Zone”.
NOTE: The timer position (time in sec.)
which is present during a suction
pressure drop from the “Control Zone”
to “Below the Control Zone” is con-
tinued without interruption. In other
words: If the loading timer is at 40
sec. in the “Control Zone” to “Below
the Control Zone” the timer will con-
tinue to count down from that point
on a pressure drop from the “Control
Zone” to “Below the Control Zone”.
However, no loading action will take
place in this pressure range.
In some cases, the timer may be be-
low 30 sec. on the transtion. In these
cases, the timer will transition back
to 60 sec. and restart.
SUCTION
PRESSURE
PSIG
“CONTROL ZONE”
“ABOVE THE CONTROL ZONE”
“BELOW THE CONTROL ZONE”
Unloading Timer: This 30 sec. timer constantly cycles
from 30 sec. to “0” and restarts at
“30”. Unloading willl occur in 30 sec.
intervals whenever the counter counts
down to “0” until the system is com-
pletely unloaded.
NOTE: The timer position (time in sec.)
which is present during a suction
pressure drop from the “Control Zone”
to “Below the Control Zone” is con-
tinued without interruption. In other
words, if the unloading timer is at 15
sec. in the “Control Zone”, the timer
will continue to count down from that
point on a pressure drop from the
“Control Zone” to “Below the Control
Zone”. After 15 sec., unloading will
take place. This still assures a mini-
mum of 30 sec. between stages of
unloading even if the timer is at “0”
when the pressure drops to “Below
the Control Zone”.
