Table of Contents
Advertisement
Unit Controls
The maximum limits for the display are:
• Suction Pressure: 200 PSIG (13.79 BARG)
• Discharge Pressure: 400 PSIG (27.58 BARG)
S Y S X
S U C T I O N
=
7 3 . 6
This message shows the suction line temperature of the
respective refrigerant system. The minimum limit on the
display for these parameters is 9.2°F (-12.7°C). The
maximum limit on the display is 85.4°F (29.7°C). The
temperature sensors for this function are optional on all
models.
S Y S
X
H O U R S
2 = X X X X X,
S Y S
X
S T A R T S
2 = X X X X X,
The first display shows accumulated running hours of
each compressor for the specific system. The second
message shows the number of starts for each compres-
sor on each system.
L O A D
T I M E R
U N L O A D
T I M E R
(Only displayed when control mode programmed for Dis-
charge Air Temperature)
This display of the load and unload timers indicate the
time in seconds until the unit can load or unload. Whether
the systems loads or unloads is determined by how far
the actual liquid temperature is from setpoint. A detailed
description of unit loading and unloading is covered un-
der the topic of Capacity Control.
C O O L I N G
2
O F
8
(Only displayed when control mode programmed for
Discharge Air Temperature)
The display of COOLING DEMAND indicates the current
"step" in the capacity control scheme. The number of
available steps are determined by how many compres-
sors are in the unit. In the above display, the "2" does not
mean that two compressor are running, but only indi-
cates that the capacity control scheme is on step 2 of 8.
Capacity Control is covered in more detail in this publi-
cation, which provides specific information on compres-
sor staging.
104
T E M P
° F
1 = X X X X X
3 = X X X X X
1 = X X X X X
3 = X X X X X
=
5 8
S E C
=
0
S E C
D E M A N D
S T E P S
L E A D
S Y S T E M
S Y S T E M
N U M B E R
(Only displayed when control mode programmed for Dis-
charge Air Temperature)
This display indicates the current LEAD system. In this
example system 2 is the LEAD system, making system
1 the LAG compressor. The LEAD system can be manu-
ally selected or automatic. Refer to the programming
under the "Options" key.
A unit utilizing hot gas bypass should be
programmed for MANUAL with System
1 as the lead system. Failure to do so will
prevent hot gas operation if System 2
switches to the lead system when pro-
grammed for AUTOMATIC LEAD/LAG.
E V A P
P U M P
E V A P
H E A T E R
This display is for chiller applications only and does not
apply to condensing units. However, the evaporator con-
tacts could be used to control the air handler. Refer to
the Unit Operation section under Evaporator Control
Contacts.
The evaporator pump dry contacts are energized when
any compressor is running, or the unit is not OFF on the
daily schedule and the unit switch is ON. However, even
if one of the above is true, the contacts will not close if
the micropanel has been powered up for less than 30
seconds, or if the contacts have been closed in the last
30 seconds to prevent motor overheating.
A C T I V E
R E M O T E
N O N E
There are several types of remote systems that can be
used to control or monitor the unit. The following mes-
sages indicate the type of remote control mode active:
NONE – No remote control active. Remote monitoring
may be via ISN
ISN
– YorkTalk via ISN (Remote Mode)
*LOAD LIM – Load limiting enabled. Can be either
stage 1 or stage 2 of limiting.
*PWM TEMP – EMS-PWM temperature reset
*Refer to the section on Operating Controls
I S
2
I S
O N
I S
O F F
C T R L
YORK INTERNATIONAL
Advertisement
Table of Contents
