Start-up and Shut-dow n
86
CVHH-SVX001A-EN
The purge condensing-unit com pressor suction
tem perature varies w ith the am ount of non-condensables
collected in the purge tank. If the am ount of non-
condensables collected in the purge tank lim its the
available condensing surface in the tank, the condensing-
unit com pressor suction tem perature begins to fall.
The purge controller initiates a pum p-out cycle w hen the
suction tem perature reaches the pum p-out initiate value
that is calculated w ithin the purge control. During the
pum p-out cycle, the sm all pum p-out com pressor pulls any
non-condensables from the purge tank and discharges
them through the carbon tank. As the non-condensables
are rem oved from the purge tank, the condensing-unit
com pressor suction tem perature increases. The purge
controller m onitors the com pressor suction tem perature
and cycles or stops the pum p-out, depending on the
tem perature that is present.
The 1/4 hp air-cooled condensing unit of the refrigeration
system operates effectively w hen it is in the operating
range show n in
Figure 50
.
Figure 49.
Adaptive chiller OFF flow chart
Fir st chiller pow er- up.
Pur ge operat es
cont inuously for 168
hour s t o collect dat a.
Chiller On or Off.
Chiller Off.
Pur ge Off.
The pur ge cont r ol r ev iew s t he hist or ical
pum p- out dat a for “ chiller On” and
“ chiller Off ” and det er m ines t he Pum pout
Tim e ( from t he last 24 hr s, or t he daily
average over t he last 7 day s, w hichever
is gr eat er ) .
Tur n pur ge Off.
Hold purge Off for
6 hour s.
Hold pur ge Off for
1 day.
Hold purge Off for
2 day s.
Hold pur ge Off for
3 day s.
I s Pum pout
Tim e less t han
5 m inut es?
I s Pum pout
Tim e less t han
3 m inut es?
I s Pum pout
Tim e less t han
1 m inut e?
I s pur ge r un
60 m inut es
w it hout
pur ging?
Run pur ge.
Yes
Yes
Yes
Yes
No
No
No
No
Summary of Contents for CVHH
Page 110: ......