Johnson Controls LSWU035 User Manual

JOHNSON CONTROLS
101
SECTION 5 – SEQUENCE OF OPERATION
FORM 145.05-NOM7
ISSUE DATE: 10/31/2019
5
A COMM ZONE TEMP (Communicated)
connection to the unit keeps the last tem-
perature input from the Building Automa-
tion System (BAS) if the communications
is interrupted.
Z
O
N
E
S
E
T
P
O
I
N
T
C
O
O
L
I
N
G
L
O
W
OCC STANDBY
ZONE TEMP IS
LESS THAN .5 °F
ABOVE ZONE
TEMP SP
SUPPLY FAN AT
100%
C
O
O
L
I
N
G
H
I
G
H
OCC COOLING LOW
ZONE TEMP IS
BETWEEN .5 °F AND
1.5 °F ABOVE THE
ZONE TEMP SP
SUPPLY FAN AT 100%
OCC COOLING HIGH
ZONE TEMP IS MORE THAN
1.5 °F ABOVE THE ZONE
TEMP SP
SUPPLY FAN AT 100%
OCC STANDBY
ZONE TEMP IS
LESS THAN .5 °F
BELOW ZONE
TEMP SP
SUPPLY FAN AT
100%
H
E
A
T
I
N
G
L
O
W
H
E
A
T
I
N
G
H
I
G
H
OCC HEATING LOW
ZONE TEMP IS
BETWEEN .5 °F AND
1.5 °F BELOW ZONE
TEMP SP
SUPPLY FAN AT 100%
OCC HEATING HIGH
ZONE TEMP IS MORE
THAN 1.5 °F BELOW THE
ZONE TEMP SP
SUPPLY FAN AT 100%
NOTES:
1- WHENEVER THE UNIT ENTERS AN ACTIVE COOLING OR HEATING MODE, THE UNIT CONTROLLER WILL UTILIZE AS MANY OR AS FEW STAGES OF COOLING or HEATING
THAT IT NEEDS TO ACHIEVE AND MAINTAIN THE ACTIVE SUPPLY AIR TEMP SP.
2- UNOCCUPIED SEQUENCE WILL BE THE SAME AS ABOVE EXCEPT THE ZONE TEMP SPs USED WILL BE THE UNOCC SP’s VALUES.
3- UNIT MODES WILL STAGE DOWN WHEN THE ZONE TEMP IS .5 °F UNDER SPs FOR COOLING AND .5 °F OVER SPs FOR HEATING.
LD010572
FIGURE 62 - CONSTANT VOLUME SETPOINT DETERMINATION
Zone Temperature Control
When the “CONTROL METHOD” is set to Zone Tem-
perature Control (either hardwired or communicated),
the “SUPPLY AIR TEMP ACTIVE SP” is determined
by the difference between the ZONE TEMP and the ap-
propriate zone setpoint. Table 19 on page 102 shows
the parameters that are used to determine the “SUPPLY
AIR TEMP ACTIVE SP.”
Where: ΔTOC = “ZONE TEMP” – “OCC ZONE
COOLING SETPOINT,” ΔTOH = “ZONE TEMP”
– “OCC ZONE HEATING SETPOINT,” ΔTUC
= “ZONE TEMP” – “UNOCC ZONE COOLING
SETPOINT,” and ΔTUH = “ZONE TEMP” – “UNOCC
ZONE HEATING SETPOINT”
Constant Volume
A Constant Volume unit with the Zone Control Method
does not have a direct effect on the control of the com-
pressor and heating stages. Instead the Zone (hardwired
or communicated) input is only used to determine the
UNIT MODE. The staging of the compressors and fac-
tory optioned heat source is always based on the “SUP-
PLY AIR TEMP ACTIVE SP.”

Johnson Controls LSWU035 Specifications

General

Brand	Johnson Controls
Model	LSWU035
Category	Chiller
Language	English