BAC-120063CW-ZEC FlexStat
6
Installation and Configuration Guide, Rev. G
NOTE:
Type II or III 10K ohm thermistors can be
selected by changing the menu setting in
ADVANCED > INPUTS
(see
NOTE:
FlexStat inputs do not support 1K ohm
RTDs.
Power Connection
Connect a KMC Controls 24 volt, Class-2 transformer
to the power terminals on the FlexStat’s backplate:
1. Connect the transformer’s
neutral
lead to the 24
VAC
Common/–/C
terminal. (See Illustration 5.)
2. Connect the AC
phase
lead to the 24 VAC
Phase/
~
/R
terminal.
Power is applied to the FlexStat when the trans-
former is powered.
KMC Controls recommends powering only one con-
troller/thermostat from each transformer. If installing
a FlexStat in a system with other controllers/thermo-
stats powered from a single transformer, however,
phasing must be correct and the total power drawn
from the transformer must not exceed its rating.
Network Wiring
For an MS/TP network, use a three-conductor cable
(Belden cable #82760 or equivalent):
1. Connect the
–A
terminals in parallel with all
other
–A
terminals on the network. (See Illustra-
tions 2 through 5.)
2. Connect the
+B
terminals in parallel with all
other
+B
terminals.
3. Connect the shields of the cable together at each
device. Use a wire nut at the FlexStat or the
S
terminal in KMC BACnet controllers. Connect
the cable shield to a good earth ground at
one
end only
.
NOTE:
The
S
terminal in KMC controllers is
provided as a connecting point for the
shield. The terminal is not connected to the
ground of the controller. When connecting
to controllers from other manufacturers,
verify the shield connection is not
connected to the controller’s ground.
NOTE:
For more information on principles and
good practices when connecting an MS/TP
.
For the bank of three relays, there is one Switched
(relay) Common connection (in place of the GND ter-
minal used with analog outputs). (See Illustration 6.)
For the relay circuit, the phase side of the AC should
be connected to the SC terminal.
FlexStat relays are
NO, SPST (Form “A”)
.
Do not attach a device that draws current exceeding
the FlexStat’s output capacity:
• Maximum output current
for individual
ANA-
LOG outputs (7–9) is 20 mA @ 12 VDC (each).
• Max. output current is 1 A for individual RE-
LAYS @ 24 VAC/VDC or a total of 1.5 A per bank
of 3 relays
(relays 1–3 and 4–6).
Input Connections
Passive input devices require pull-up resistors in the
circuit. For a
passive
input device (a
DAT
10K ohm
thermistor on IN2), set (if not in the default position)
the pull-up switches on the back of the circuit board
to the
10K ohm
position, with the upper switch to the
left and lower switch to the right. (See Illustration 8.)
NOTE:
IN2 must also be configured in the menu for
DAT.
See
Configuration and Operation on
For an
active
voltage device (optional 1–5 VDC static
pressure reading from a
CSP-4702
on IN9), set the
switches to the
0–12 VDC
position, with the upper
switch to the right and lower switch to the left.
NOTE:
Unlike the EOL switch pairs, the
INPUT
switch pairs must NOT have both switches
set to the same direction
—if one of the
pair’s switches is set to the left, for example,
the other must be set to the right (or vice
versa).
ALL the input pull-up resistor
switch pairs must be fully latched in either
10K Ohm or 0–12 VDC position even if
a switch pair has no input connected!
A
single incorrect switch position may cause
errors in multiple inputs.
Illustration 6—Switched (Relay) Common and Relays
Relay 3
(
or 6
)
SC (Phase) 1–3
(
or 4–6
)
Relay 2
(
or 5
)
Relay 1
(
or 4
)
One Switched
Common
Connection
Per Bank of
Three
Normally
Open Relays
