Johnson Controls 100 Series Manual

JOHNSON CONTROLS
25
FORM 100.50-SU8
ISSUE DATE:1/28/2016
9
Series 100 units have the ability to reset the duct static
pressure SP. This can be done in one of two ways, by
a 0-5 VDC signal to CTB1 terminals DSP+ and DSP-,
or from a 0-5 command from a building automation
system.
To reset the duct static pressure SP, the following val-
ues must be entered:
• DSP_HI_LIMIT (AV03) Duct Static Pressure
High Limit
• DSP_LO_LIMIT (AV04) Duct Static Pressure
Low Limit
There is also an option in the unit service menu that
must be enabled. That option, “Duct Pres RST BAS”
must be enabled for duct static pressure reset from a
BAS.
Once the DSP hi and DSP lo values are entered, the
BAS will send the 0 or 5 command to the following
point:
• DSP_RST_BAS (AV05) Duct Static Pressure Re-
set BAS
The unit controller will reset the duct static pressure SP
according to the BAS command as follows:
• When the BAS command is 0, the unit controller
will set the Active DSP SP to the DSP High Limit
• When the BAS command is 5, the unit controller
will set the Active DSP SP to the DSP Low Limit
• When the BAS command is somewhere between
0 and 5, the unit controller will reset the Active
DSP SP to a percentage down from the DSP Hi
Limit based on a percent of the difference be-
tween the DSP Hi and the DSP Lo
Example:
• DSP_HI_LIMIT (AV03): 2.00” wc
• DSP_LO_LIMIT (AV04): 1.00” wc
A command of 0, Active DSP SP=2.00” wc
A command of 1.25, Active DSP=1.75” wc
A command of 2.5, Active DSP SP= 1.50” wc
A command of 3.75, Active DSP=1.25” wc
A command of 5, Active DSP=1.00”wc.
The percent of reset can be read at point DCT_ST_PR_
RT (AI16) Duct Static Press Reset
The actual Duct Static Pressure can be read at point
DCT_STAT_PRS (AI17) Actual Duct Static Pressure
The Active DSP SP can also be reset by simply writing
to the DSP_HI_LIMIT (AV03) point whenever a duct
static SP change is required. If this is the option chosen,
just remember that the DSP_HI_LIMIT (AV03) cannot
be lower than the DSP_LO_LIMIT (AV04). The best
way to do this is set the DSP_LO_LIMIT (AV04) to
0.00 “ wc and then the DSP_HI_LIMIT (AV03) will
have a range of 0.00” wc to the max of the duct static
transducer range, typically 5.00” wc. There is a factory
default setpoint to lock out the unit if the duct static
reaches or exceeds 3.00’ WC
SECTION 9 - DUCT STATIC PRESSURE RESET (BAS)
DUCT STATIC RESET
HIGH SETPOINT
Active DSP
Setpoint
DUCT STATIC RESET
LOW SETPOINT
0 Volts
5 VoltsDuct Static Pressure Reset
Voltage (Volts DC)
A 2.5 VDC hardwired signal or
a 2.5 communicated signal will
reset Duct Static Pressure to
1.5" WC.
2.0" WC
1.0" WC

Johnson Controls 100 Series Specifications

General

Brand	Johnson Controls
Model	100 Series
Category	Air Conditioner
Language	English