York YVAA, Installation, Operation & Maintenance Instructions Manual, Page: 147 / 178

SECTION 8 - MICROPANEL
JOHNSON CONTROLS
147
FORM 201.28-NM1.1
ISSUE DATE: 1/31/2018
8
LD10605
PROGRAM
KEY
PROGRAM KEY
Program Key Operation
Various operating parameters are programmable by the
user. These are modified by pressing the PROGRAM
key and then the

(ENTER) key to enter Program
Mode. A listing of the limits of the programmable val-
ues is found below. Note that the Imperial units are ex-
act values, while Metric units are only approximate.
The ▲ and ▼ ( ARROW) keys are used to scroll
through the user programmable values. A value may be
changed by keying in the new value and pressing the

(ENTER) key to store the new value in memory. The
cursor will be displayed on the screen when a number
key is pressed. The first line of each message will indi-
cate the chiller default (DEF) value), lowest acceptable
programmable value (LO), and highest acceptable pro-
grammable value (HI). The user programmable value
is programmed ON in the second line of the message.
When the PROGRAM key is first pressed, the follow-
ing display will appear indicating the user is in the pro-
gram mode:
PROGRAM MODE XXXX
PRESS ENTER KEY TO CONTINUE
Pressing the

(ENTER) key again will display the
first programmable selection.
Suction Pressure Cutout
PROGRAM ◄DEF XXXXX LO XXXXX HI XXXXX
SUCTION PRESSURE CUTOUT = XXX.X PSIG
The suction pressure cutout is protects the chiller from
a low refrigerant condition. It also helps protect from
a freeze-up due to low or no chilled liquid flow. How-
ever, it is only a back-up for a flow switch and cannot
protect against an evaporator freeze under many condi-
tions. This cutout is programmable and should gener-
ally be programmed for 1.65 barg (24 PSIG) for chilled
water cooling for R-134a system, and 1.93 barg (28
PSIG) for R-513A system.
For R-134a refrigerant, the cutout is programmable be-
tween 1.65 and 2.48 barg (24.0 and 36.0 PSIG) in the
Water Cooling mode and 0.34 and 2.28 barg (5.0 and
36.0 PSIG) in the Glycol Cooling mode. The default
value for both modes will be 1.65 barg (24.0 PSIG).
For R-513a refrigerant, the cutout is programmable be-
tween 1.93 and 2.80 barg (28.0 and 40.7 PSIG) in the
Water Cooling mode and 0.53 and 2.80 barg (7.7 and
40.7 PSIG) in the Glycol Cooling mode. The default
value for both modes will be 1.93 barg (28.0 PSIG).