KMC Controls BAC-7401 Operating instructions

Section 1
About the BAC-7401
Specifications ...........................................................................................................................3
Accessories ..............................................................................................................................5
Safety considerations .............................................................................................................6
Section 2
Installing the controller
Mounting .................................................................................................................................7
Connecting inputs ..................................................................................................................7
Connecting outputs ................................................................................................................8
Connecting to a NetSensor ....................................................................................................9
Connecting to an MS/TP network .......................................................................................9
Connecting power ................................................................................................................11
Programming ........................................................................................................................12
Section 3
Operating the controller
Operation ...............................................................................................................................13
Controls and Indicators .......................................................................................................13
Restoring factory settings ....................................................................................................16
Installation and Operation Guide
BAC-7401 and BAC-7401C
Advanced Applications Controller
for Heat Pump Applications
905-019-57ERevision E

KMC Controls
Revision E2
Important notices ©2012, KMC Controls, Inc.
WinControl XL Plus, NetSensor, and the KMC logo are registered trademarks of
KMC Controls, Inc.
BACstage and TotalControl are trademarks of KMC Controls, Inc.
MS/TP automatic MAC addressing is protected under United States Patent
Number 7,987,257.
All rights reserved. No part of this publication may be reproduced, transmitted,
transcribed, stored in a retrieval system, or translated into any language in any form
by any means without the written permission of KMC Controls, Inc.
Printed in U.S.A.
Disclaimer The material in this manual is for information purposes only. The contents and the
product it describes are subject to change without notice. KMC Controls, Inc. makes
no representations or warranties with respect to this manual. In no event shall KMC
Controls, Inc. be liable for any damages, direct or incidental, arising out of or related
to the use of this manual.
KMC Controls
P. O . B o x 4 9 7
19476 Industrial Drive
New Paris, IN 46553
U.S.A.
TEL: [phone]
FAX: [phone]
E-mail: [email protected]

BAC-7401 Heat Pump Controller
Revision E 3
SECTION 1
About the BAC-7401
This section provides a general description of the KMC Controls
BAC-7401 controller. It also introduces safety information. Review
this material before installing or operating the controller.
The BAC-7401 is a native BACnet, fully programmable controller designed to
control heat pump units. Use this versatile controller in stand-alone environments or
networked to other BACnet devices. As part of a complete facilities management
system, the BAC-7401 controller provides precise monitoring and control of
connected points.
◆BACnet MS/TP compliant
◆Automatically assigns the MAC address and the device instance
◆Triac outputs for direct connection to 24-volt control circuits
◆Supplied with programming sequences for heat pump units
◆Easy to install, simple to configure, and intuitive to program
◆Controls heat pump compressor, fan, reversing valve and auxiliary heat.
Specifications Inputs
Universal inputs 4
Key features Software selectable as analog, accumulator or binary
objects.
Standard units of measure.
NetSensor compatible
Overvoltage input protection
Pull–up resistors Switch select none or 10k.
Connector Removable screw terminal block, wire size
14–22 AWG
Conversion 10–bit analog–to–digital conversion
Pulse Counting Up to 16 Hz
Input range 0–5 volts DC
NetSensor Compatible with models KMD-1161 and KMD-1181.
Triac outputs 4
Key features Optically isolated triac output.
Programmable a binary object.
Connector Removable screw terminal block
Wire size 14-22 AWG
Output range Maximum switching 30 volts AC at 1 ampere

KMC Controls
Revision E
About the BAC-7401
Specifications
4
Communications
BACnet MS/TP EIA–485 operating at rates up to 76.8 kilobaud.
Automatic baud detection.
Automatically assigns MAC addresses and device
instance numbers.
Removable screw terminal block.
Wire size 14–22 AWG
NetSensor Compatible with models KMD-1161 and KMD-1181,
Connects through RJ–12 connector.
Programmable features
Control Basic 10 program areas
PID loop objects 4 loop objects
Value objects 40 analog and 40 binary
Time keeping Real time clock with power backup for 72 hours
(BAC-7401-C only)
See PIC statement for supported BACnet objects
Schedules
Schedule objects 8
Calendar objects 3
Trend objects 8 objects each of which holds 256 samples
Alarms and events
Intrinsic reporting Supported for input, output, value, accumulator,
trend and loop objects.
Notification class objects 8
Memory Programs and program parameters are stored in
nonvolatile memory.
Auto restart on power failure
Application programs KMC Controls supplies the BAC-7401 with
programming sequences for heat pump units:
◆Roof top operation based on occupancy, night
setback, proportional hot and chilled water valve
control.
◆ Economizer operation.
◆ Freeze protection.
Regulatory UL 916 Energy Management Equipment
FCC Class B, Part 15, Subpart B
BACnet Testing Laboratory listed
CE compliant
SASO PCP Registration KSA R-103263

BAC-7401 Heat Pump Controller
Revision E
About the BAC-7401
Accessories
5
Environmental limits
Operating 32 to 120° F (0 to 49° C)
Shipping –40 to 140° F (–40 to 60° C)
Humidity 0–95% relative humidity (non-condensing)
Installation
Supply voltage 24 volts AC (–15%, +20%), 50-60 Hz, 25 VA, Class 2
only, non-supervised (all circuits, including supply
voltage, are power limited circuits)
Weight 8.2 ounces (112 grams)
Case material Flame retardant black plastic
Models
BAC-7401C BACnet RTU controller with real-time clock
BAC-7401 BACnet RTU controller without real-time clock
Dimensions
Accessories Power transformer
XEE-6111-40 Single-hub 120 volt transformer
XEE-6112-40 Dual-hub 120 volt transformer
Table 1-1 BAC-7401 Dimensions
A B C D E
4.36 in. 6.79 in. 1.42 in. 4.00 in. 6.00 in.
111 mm 172 mm 36 mm 102 mm 152 mm
T4 RTN T3 T2 RTN T1
A
E
B
C
D

KMC Controls
Revision E
About the BAC-7401
Safety considerations
6
Safety
considerations KMC Controls assumes the responsibility for providing you a safe product and
safety guidelines during its use. Safety means protection to all individuals who
install, operate, and service the equipment as well as protection of the equipment
itself. To promote safety, we use hazard alert labeling in this manual. Follow the
associated guidelines to avoid hazards.
Danger
Danger represents the most severe hazard alert. Bodily harm or death will
occur if danger guidelines are not followed.
Warning
Warning represents hazards that could result in severe injury or death.
Caution
Caution indicates potential personal injury or equipment or property damage
if instructions are not followed.
Note
Notes provide additional information that is important.
Detail
Provides programing tips and shortcuts that may save time.

BAC-7401 Heat Pump Controller
Revision E 7
SECTION 2
Installing the controller
This section provides a brief overview of the BAC-7401 and the
BAC-7401C BACnet heat pump controllers. Review this material
before you begin installing the controller.
Mounting Mount the controller inside of a metal enclosure. KMC Controls recommends using
a UL-approved Enclosed Energy Management Equipment Panel such as a KMC
model HCO–1034, HCO–1035 or HCO–1036. Insert #6 hardware through the four
mounting holes on the top and bottom of the controller to securely fasten it to a flat
surface. See Dimensions on page 5 for mounting hole locations and dimensions. To
maintain RF emission specifications, use either shielded connecting cables or enclose
all cables in conduit.
Connecting inputs The BAC-7401 controller has four universal inputs. Each input can be configured to
receive either analog or digital signals. By using the optional pull-up resistors, either
passive or active devices may be connected to the inputs.
Note
KMC supplied Control Basic programs assign input 1 (I1) to the space
temperature sensor input. If the KMC programs are not in use or are modified,
input 1 is available for other use. Inputs 2, 3 and 4 are not assigned by KMC
programs and are available as needed.
Pull–up resistors
For passive input signals, such as thermistors or switch contacts, use a pull-up
resistor. For KMC thermistors and most other applications set the switch to the On
position. See Illustration 2-1 for the pull-up switch location.
Illustration 2-1 Pull-up resistors and input terminals
T4 RTN T3 T2 RTN T1
1
BAC-7401 cover removed.
Off On

KMC Controls
Revision E
Installing the controller
Connecting outputs
8
4–20 mA inputs
To use a 4–20 current loop input, connect a 250 ohm resistor from an input to
ground. The resistor will convert the current input to a voltage which can be read by
the controller analog-to-digital converter. Set the pull-up switch to the Off position.
Ground terminals
Input ground terminals are located next to the input terminals. Up to two wires, size
14–22 AWG, can be clamped into each ground terminal. If more than two wires must
be joined at a common point, use an external terminal strip to accommodate the
additional wires.
Pulse inputs
Connect pulse inputs under the following conditions:
◆If the pulse input is a passive input such as switch contacts, then place the
input pull-up in the On position.
◆If the pulse is an active voltage (up to a maximum of +5 volts DC ), then place
the input pull-up jumper in the Off position.
Connecting
outputs The BAC-7401 outputs are single-stage triacs designed to directly switch 24-volt ac
circuits.
Caution
When connecting loads to triacs, use only the terminal marked RTN associated
with each triac for the 24-volt ciruit.
Illustration 2-2 Output terminals
T4 RTN T3 T2 RTN T1
1
T4 RTN T3 T2 RTN T1
Triac 3 and 4
output and
return
Triac 1 and 2
output and
return

BAC-7401 Heat Pump Controller
Revision E
Installing the controller
Connecting to a NetSensor
9
Connecting to a
NetSensor The Network RJ–12 connector provides a connection port to a NetSensor model
KMD-1161 or KMD-1181. Link the controller to a NetSensor with a KMC Controls
approved cable up to 75 feet long. See the installation guide supplied with the
NetSensor for complete NetSensor installation instructions.
Connecting to an
MS/TP network Connections and wiring
Use the following principles when connecting a controller to an MS/TP network:
◆Connect no more than 128 addressable BACnet devices to one MS/TP network.
The devices can be any mix of controllers or routers.
◆To prevent network traffic bottlenecks, limit the MS/TP network size to 60
controllers.
◆Use 18 gauge, twisted pair, shielded cable with capacitance of no more than
50 picofarads per foot for all network wiring. Belden cable model #82760 meets
the cable requirements.
◆Connect the -Aterminal in parallel with all other - terminals.
◆Connect the +Bterminal in parallel with all other + terminals.
◆Connect the shields of the cable together at each controller. For KMC BACnet
controllers use the Sterminal.
◆Connect the shield to an earth ground at one end only.
◆Use a KMD–5575 repeater between every 32 MS/TP devices or if the cable
length will exceed 4000 feet (1220 meters). Use no more than seven repeaters
per MS/TP network.
◆Place a KMD–5567 surge surpressor in the cable where it exits a building.
Illustration 2-3 Connection to a NetSensor
T4 RTN T3 T2 RTN T1
75 feet Max.

KMC Controls
Revision E
Installing the controller
Connecting to an MS/TP network
10
See Application Note AN0404A, Planning BACnet Networks for addional information
about installing controllers.
Note
The BAC-7401 EIA–485 terminals are labeled -A, +B and S. The Sterminal 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 ground.
End of line termination switches
The controllers on the physical ends of the EIA-485 wiring segment must have end-
of-line termination installed for proper network operation. Set the end-of-line
termination to On using the EOL switches.
Illustration 2-4 MS/TP network wiring
S
+B
-A
S
+B
-A
S
+B
-A
S
+B
-A
Illustration 2-5 End of line termination
Set end-of-line termination to
On in these controllers only.