ACL CSC400 User manual

805 Main Ave. West – Box 2002 Sundre, Alberta T0M 1X0 – Phone: [phone] – Fax: [phone] – Email: [email protected]
Website: www.aclmfg.com
Installation and Operations Manual
for the
CSC400 Combustion
Safety Controller
(Rev 1D)
WARNING
This manual must be read in its entirety before installation of this controller.
Installation must be performed by a qualified technician and must adhere to
the standards set by the local regulatory authorities.
ACL is not responsible for the misuse or incorrect application of this product.
V 2.21

Table of Contents
Introduction....................................................................................................................................................................................4
CSC400 Features............................................................................................................................................................................ 5
Operation Summary ....................................................................................................................................................................... 6
Quickstart Installation Procedure - CSC400 Combustion Safety Controller ................................................................................. 7
Input and Control Connections............................................................................................................................................10
Solenoid Output Connections, Ignitor 1 and 2..................................................................................................................... 18
CSC400 Front Panel Buttons and LED Display.................................................................................................................. 20
Adjusting Temperature Setpoints and Deadbands...............................................................................................................22
Wiring Diagrams - FI (Flame Ionization)............................................................................................................................ 23
CSC400 Controller Menu System................................................................................................................................................28
CSC400 Menu Structure Summary Chart ...........................................................................................................................28
Top Menu Options............................................................................................................................................................... 32
Configuration Menu Options............................................................................................................................................... 32
Line Display Configuration Menu Options .........................................................................................................................33
Show Last IGN SD Menu Options...................................................................................................................................... 34
View TMain 1 / 2 Menu Options.........................................................................................................................................34
Solenoid Drivers Menu Options .......................................................................................................................................... 35
Time and Date Set Menu Options .......................................................................................................................................35
Modbus Settings Menu Options ..........................................................................................................................................35
4-20mA Output (1 / 2) Menu Options ................................................................................................................................. 36
4-20mA Input Level / Pressure (1 / 2) Menu Options ......................................................................................................... 38
AUX1 & AUX2 Relay Settings Menu Options................................................................................................................... 38
Modbus Communications ............................................................................................................................................................ 39
Modbus/RS-485 Cable Connections – Field Installations................................................................................................... 39
Commonly Used CSC400 Modbus Registers...................................................................................................................... 41
Additional CSC400 Feature Details.............................................................................................................................................46
Latched versus Unlatched Shutdowns................................................................................................................................. 46
Intermittent (Pilotless) or Continuous Pilot Feature ............................................................................................................ 46
Purge Cycle Feature............................................................................................................................................................. 47
TC3 Auxiliary High Temperature Shutdown ......................................................................................................................47
Low Temperature Shutdown/Alarm....................................................................................................................................47
Dual TC1/TC2 Difference Shutdown..................................................................................................................................47
CSC400 Controller Shutdown Display Codes.....................................................................................................................48
4-20mA Input Connection Notes for Rev 1D CSC400 Boards........................................................................................... 51
4-20mA Input DIP Switches................................................................................................................................................51

4-20mA Output Connection Notes for Rev 1D CSC400 boards......................................................................................... 52
DIP Switch Option Settings.................................................................................................................................................53
Appendix A - CSC400 Rev 1D Technical Specifications............................................................................................................ 54
Appendix B - Modbus/RS-485 Cabling Technical Details .......................................................................................................... 56
RS-485 Signal Naming Conventions...................................................................................................................................56
Half-Duplex vs Full-Duplex................................................................................................................................................ 56
Cable Types......................................................................................................................................................................... 56
Wiring topology................................................................................................................................................................... 57
Line Polarization.................................................................................................................................................................. 57
Termination ......................................................................................................................................................................... 58
Number of Allowed Devices on the RS-485 .......................................................................................................................58
Slew Rate............................................................................................................................................................................. 58
Isolated (or Common) Ground............................................................................................................................................. 58
Appendix C - Programming a New Modbus Slave ID (Address) ................................................................................................ 59
Appendix D - Troubleshooting ....................................................................................................................................................60
Additional Documents
The following additional documents for the CSC400 Combustion Safety Controller are available.
Document Filename
Document Description
CSC400_Modbus_Installation_Manual.pdf
Modbus documentation containing more in-depth register
descriptions and additional technical details.

4
Introduction
The ACL CSC400 is a leading-edge Combustion Safety Controller that provides burner ignition and full first-out annunciation
of all the shutdown inputs such as Level, High Temperature, High/Low Gas, Remote Shutdown, Pressure, Proof of Closure,
Flame Failure, Power Failure, Auxiliary 1 & 2 and more. The CSC400 monitors three separate thermocouple inputs that can
be utilized for temperature control in process applications such as tanks, line heaters, re-boilers or any other application where
accurate temperature monitoring and/or control is required. The CSC400 also provides two independent 4-20mA Inputs (level,
pressure, temperature) which can be configured as latched Low or High shutdowns. The system is designed to operate with or
without a continuous pilot.
The CSC400 controller can be configured for a wide variety of systems:
Application
Configuration / Mode
Burners,
Combustion
Safety Control,
Incinerators
CSC400 Flame Ionization (FI) System
The CSC400 Flame Ionization (FI) System incorporates dual burner control. Each burner includes
ignition control and three solenoid outputs (Pilot, Main, Temperature Main). The CSC400 uses a
high voltage sparker to light the continuous or intermittent pilot burner. It uses a single
ignitor/flame rod to provide both flame acknowledgment and ignition per pilot burner. Either or
both burners may be enabled. An alarm will signal if the CSC400 detects that either the pilot is out,
or the flame failed to light. Once the Start button is pressed on the front of the unit, the CSC400
will automatically start sparking up to a maximum of three ignition trials providing that all
shutdowns are in a permissive state.The CSC400 can be configured to have both burners shut off if
one goes into Flame Fail, or have one remain running while indicating an alarm.
Six membrane push buttons on the face of the controller are provided: Stop/Reset, Start, Menu, Select, Up, and Down. All
options can be adjusted with the membrane push buttons on the face of the controller (including the three independent
thermocouple temperature set points). The 4-line, 20-character LED display can be configured in a variety of ways to show the
measured temperature values, temperature setpoints, 4-20mA input values, igniter/burner and solenoid status (on/off).Various
user preferences can be configured through the menu system and DIP switches including a variety of display options,
temperature ranges, shutdown latch control, 4-20 input/output configuration, temperature unit display, and dead band range
selection.
The CSC400 Controllers are able to communicate remotely with Modbus Master Devices. A Modbus Master Device may be a
Programmable Logic Controller, a PC, or another device. The CSC400 Controller is a Modbus Slave Device that implements
the Modbus RTU protocol on an RS-485, half-duplex, physical connection. The default Modbus communication parameters
are 9600 baud, 8 data bits, no parity bits, one stop bit (“8N1”), Modbus Slave ID (Modbus address) 2.

5
CSC400 Features
CSC400 Controller Features List
•
No complex programming required. Simple menu interface provided to enable/disable burners and adjust
temperature setpoints
•
Dual burner system with three solenoid outputs each (6 total).
•
12/24VDC operation. Solar capable as well.
•
CSA approved for Class I, Div 2 locations
•
Operational ambient temperature of -40° to +60° Celsius
•
CSA approved C22.2 No 199-M89. Combustion safety controls and solid-state Ignitors for Gas & Oil burning
equipment
•
CSA B149.3 - 10 compliant, meets NFPA standards
•
Type 4x enclosure, corrosive resistant and weatherproof
•
Modbus RTU (over RS485) communications capability with full status and Shutdown logging readout
•
100% fail safe design
•
Local and Remote On/Off controls
•
Brownout Protection. CSC400 will continue in previous state if a brownout/blackout condition is detected.
•
First out annunciation of shutdowns
•
Safety lockout for high temperature setting
•
Onboard solenoid driver option for power reduction to solenoids and peak-hold solenoids. Each solenoid can be
set to an independent low-power setting.
•
Onboard solenoid output short circuit detection and notification (via LED display and Alarm Status)
•
Three adjustable type-K thermocouple inputs for monitoring three separate temperature points (2 process temp.
& 1 high temp.)
•
Pilotless burner control selectable.
•
Provides control logic for FI (flame ionization) ignition systems (burners, incinerators)
•
Five Shutdown inputs (dry contact switches required): High/Low Gas (ie: pressure shutdown), Level Shutdown,
and Auxiliary 1 & 2 Shutdowns. Additional shutdowns may be added in series. Any shutdown turns off both
burners.
•
Two isolated, fail-safe, solid-state, auxiliary, configurable relay outputs (NC, COM, NO : NC-COM in Alarm
state, NO-COM when burner(s) is(are) on)
•
Two 4-20mA powered outputs. Can be configured to output any of the three thermocouples as either a linear
temperature output or a proportional valve output around the selected setpoint temperature. Proportional valve
range is adjustable up to +/- 100°C (200°C total) around the setpoint for smoother temperature transitions. Can
also be configured to output either of the 4-20 Input readings (eg. to an external PLC).
•
Two 4-20mA (or 1V-5V) inputs with local power-sourcing availability (1A combined current limit for 4-20mA
Inputs and Outputs). Can be configured to alarm and shutdown, or alarm only upon reaching user-defined High
and/or Low levels. May also be used with 4-20mA transmitters for setpoint control of either or both burner
outputs. An OR-ing scheme is used if both 4-20mA Inputs use setpoint control on the same burner. Custom
range and units may be selected.
•
Thermocouple range: -60°C to 1200°C (-75°F to 2192° F) (Type-K Thermocouple)
•
Adjustable thermocouple dead band from 1 - 5°C or 2 - 10°F
•
Easy to read four-line, 20 character LED display indicating thermocouple temperature values, 4-20mA inputs,
shutdowns, and On or Off status for both burners
•
°C or °F readout

6
Operation Summary
Supply 12/24VDC to Main Input Power connections on the CSC400 Controller, referring to "Figure 1 – CSC400 Controller
Main Board, Top View" on page 7. The 4-line LED display will turn on and show the desired process temperatures, 4-20mA
input levels/pressures, ignitor and solenoid status, and any shutdowns active. The CSC400's menu system is accessed and
controlled via four membrane push buttons on the front panel: Menu, Select, Up, and Down. Once temperature setpoints are
set to the proper values for the desired process (heater, boiler, etc.), and additional options are configured, the Start button can
be pressed to start the CSC400 system.
When the Start button is pushed and the controller is calling for heat (measured temperatures are below the setpoint
temperatures), the controller will attempt ignition and the pilot solenoid output will provide voltage to the pilot solenoid valve,
providing pilot gas for ignition. Shutdowns, POC, and Remote Start/Stop terminals must be in a permissive state for this to
occur. Pilot solenoid output will cease if there is a failure to light within five seconds. "FF" will appear and blink on the
display indicating "Flame Fail". The CSC400 controller will attempt to light the pilot two more additional tries before locking
out, even when using a single try ignition module. If the Flame Fail status persists after three tries, this condition can be reset
either by the local Stop/Start buttons, the Remote Start/Stop switch terminals, or via Modbus Remote Stop/Start command.
Main solenoid valve outputs will be turned on 10 seconds minimum after it is confirmed that the pilot has been lit (adjustable
up to 120s). The Intermittent/Continuous Pilot Menu setting selects the behavior of the controller once all solenoids are
opened.
In Pilotless/Intermittent pilot mode (I), once the measured temperature on thermocouple 1 reaches the TC1 setpoint
temperature (but TC2 temp is still below the TC2 setpoint), all solenoid valves will be turned off.
In Continuous pilot mode (C), once the measured temperature on thermocouple 1 reaches the TC1 setpoint temperature (but
TC2 temperature is still below the TC2 setpoint), only the T/Main solenoid valve is turned off. The Pilot and Main solenoid
outputs will remain on as long as all shutdowns and POC remain permissive.
When Flame Ionization mode is selected, thermocouple 2 is used as a "high-temp" shutdown safety control for both
Intermittent and Continuous modes. All solenoid outputs and the ignition module will be turned off if the measured
temperature on thermocouple 2 is above the TC2 setpoint. An option to use thermocouple 3 as an auxiliary high-temp
shutdown is available as well.
The CSC400 has a hardware revision of 1D and firmware version 00.02.09 (minimum). The menus in this version of the
manual show firmware version 00.02.56.
THIS EQUIPMENT IS SUITABLE FOR USE IN CLASS1 DIVISION 2, GROUPS
A,B,C & D OR NON-HAZARDOUS LOCATIONS ONLY
WARNING - EXPLOSION HAZARD - SUBSTITUTION OF COMPONENTS MAY
IMPAIR THE SUITABILITY FOR CLASS 1 DIVISION 2
WARNING: EXPOSURE TO SOME CHEMICALS MAY DEGRADE THE SEALING
PROPERTIES OF MATERIALS USED IN THE FOLLOWING DEVICES:
Twelve-position DIP switch S1
Four-position, half-pitch DIP switch SW8
Eight-position DIP switch SW2

7
Quickstart Installation Procedure - CSC400 Combustion Safety Controller
Figure 1 – CSC400 Controller Main Board, Top View
The Quickstart Installation Instructions assumes the user has some familiarity
with Combustion Safety Controller Installation.

8
#
Name
Category
Description
1
Display Headers
Display
OLED Display: 16-pin header connector that the CSC400 display flex cable
connects to.
VFD Display: 14-pin header
There are also two vertical headers (5-pin/6-pin) for alternate cabling for the
displays.
2
Control Processor
Programming
Header
Programming
Programming header (factory use only) for reprogramming the onboard
Control microcontroller.
3
Communications
Processor
Programming
Header
Programming
Programming header (factory use only) for reprogramming the onboard
Communications microcontroller (Ethernet & USB functionality only. RS485
Modbus communications is performed by the Control microcontroller).
5
DIP Switches
Inputs/Control
DIP switches for user options configuration (see "DIP Switch Option
Settings" section on page 53).
6
"AUX1 Relay" &
"AUX2 Relay"
Output (dry
contacts, solid
state, 120mA max
for each)
Control
"AUX1 Relay" & "AUX2 Relay" outputs are present to allow users to control
external valves, switches, or other controls based on the TC1/2/3
measurements. Each relay contact can be controlled by any of the three
thermocouples.
- AUX1/2 Relays: "NC" and "COM" are connected together if TC
measurement is lower than the selected setpoint.
The thermocouple used for the "AUX1 Relay" and "AUX2 Relay" (and the
mode) can be changed using the menu system on the front panel of the
CSC400. See the section titled: "AUX1 Relay & AUX2 Relay Outputs" on
page 16.
7,
8
Expansion
Module Locations
Expansion
Locations for future expansion modules.
9
Spare Fuses
Power
Spare 6.3A fuses for field servicing.
10
Keypad / Overlay
Header
Inputs/Control
5-pin Header connector that the flex cable from the Keypad overlay on the
front panel connects to.
The CSC400 will shut off all ignitor outputs and solenoid valves if the overlay
is unplugged.
12
Modbus DIP
Switch
Modbus/RS485
DIP switches for selecting termination options for the Modbus/RS485
communications cable
13
Modbus
Terminals
Modbus/RS485
Terminals for connecting a Modbus/RS485 communications cable. CSC400 is
a Modbus RTU slave in a 8N1, 9600 baud default configuration.
14
Thermocouple 1
Inputs/Control
Thermocouple 1 input terminal connections. Ensure proper polarity for
correct operation. Use ungrounded thermocouples.
15
Thermocouple 2
Inputs/Control
Thermocouple 2 input terminal connections. Ensure proper polarity for
correct operation. Use ungrounded thermocouples.
16
Thermocouple 3
(optional)
Inputs/Control
Thermocouple 3 input terminal connections. Ensure proper polarity for
correct operation. Use ungrounded thermocouples.
17
4-20mA (or 1V-
5V) Level Input
Inputs/Control
Terminals for connecting a 4-20mA (or 1V-5V) transmitter indicating a Level
input for controlling CSC400 shutdown or for process measurement.
Complete configuration of this input is provided using the menu system (See
4-20mA Input Level / Pressure (1 / 2) Menu Options
on page 38).
18
4-20mA (or 1V-
5V) Pressure
Input
Inputs/Control
Terminals for connecting a 4-20mA (or 1V-5V) transmitter indicating a
Pressure input for controlling CSC400 shutdown or for process measurement.
Complete configuration of this input is provided using the menu system (See
4-20mA Input Level / Pressure (1 / 2) Menu Options
on page 38).
19
4-20mA Output 1
Output Status
The 4-20mA output generates a current output relative to the measured
temperature on either TC1, TC2, or TC3 (selectable via the menu system).
This output can be configured as either a direct temperature conversion, a
proportional valve output, or it can output either 4-20mA Input reading

9
(emulating a "splitter" mode).
20
4-20mA Output 2
Output Status
The 4-20mA output generates a current output relative to the measured
temperature on either TC1, TC2, or TC3 (selectable via the menu system).
This output can be configured as either a direct temperature conversion, a
proportional valve output, or it can output either 4-20mA Input reading
(emulating a "splitter" mode).
21
Proof of Closure
Inputs/Control
Proof of Closure input terminal connections
22
Remote Start/Stop
Inputs/Control
Remote Start/Stop input terminal connections
23
High Gas
Shutdown
Inputs/Control
High Gas Shutdown input terminal connections
24
Low Gas
Shutdown
Inputs/Control
Low Gas Shutdown input terminal connections
25
Level Shutdown
Inputs/Control
Level Shutdown input terminal connections
26
Auxiliary
Shutdown 1
Inputs/Control
Auxiliary Shutdown 1 input terminal connections
27
Auxiliary
Shutdown 2
Inputs/Control
Auxiliary Shutdown 2 input terminal connections
28
Alarm Status
Alarm (Dry
Contacts)
Alarm Status output terminal connections
29
Main Power Input
Terminals
Power
Main 12-24VDC input terminal connections
30
Ground Terminals
Power
Extra earth ground terminal connections to assist in providing stable ground
connections for solenoids, ignition modules, or other hardware
31
Ignition Module
Mounting
Location
Hardware
The Ignition Module Mounting Location indicates the area where the ACL
Ignition Module may be installed.
33
"To Igniter 2"
Ignition Module
Terminals
Control
ACL Ignition Module 2 input terminal connections: "P"ower, "A"larm,
"V"alve, Ground.
"IGN2" can be enabled or disabled using the menu system.
34
Solenoid Relay
Terminals for
IGN2
Output
Solenoids: IGN2
Terminals used for controlling power delivery to the solenoid valves for
Ignitor 2.
35
IGN2 P/M &
Main Fuse
Power
Main 6.3A Input Fuse for Control Electronics & "IGN2" Pilot and Main
Solenoids.
36
TMain 1/2 Fuse
Power
Input 6.3A Fuse for TMain Solenoids for "IGN1" and "IGN2".
37
IGN1 P/M &
Main Fuse
Power
Input 6.3A Fuse for "IGN1" Pilot and Main Solenoids.
38
"To Igniter 1"
Ignition Module
Terminals
Control
ACL Ignition Module 1 input terminal connections: "P"ower, "A"larm,
"V"alve, Ground.
"IGN1" can be enabled or disabled using the menu system.
39
Solenoid Relay
Terminals for
IGN1
Output
Solenoids: IGN1
Terminals used for controlling power delivery to the solenoid valves for
Ignitor 1.

10
Input and Control Connections
Refer to the below diagram when reading the Input and Control Connections section.
Figure 2 - CSC400 Input and Control Connections

11
The following inputs directly control 12VDC power output to the ignition modules and must be connected to dry contacts:
Input and Control Connections
Requiring Dry Contacts
Voltage on Control Inputs
Output and Control Connections
That Are Dry Contacts
Proof Of Closure
12VDC
Remote Start/Stop
12VDC
High Gas (Pres) Shutdown
12VDC
Low Gas (Pres) Shutdown
12VDC
Level Shutdown
12VDC
Auxiliary Shutdown 1
12VDC
Auxiliary Shutdown 2
12VDC
N/A
AUX1 Relay
N/A
AUX2 Relay
Alarm Status
N/A
Alarm Status
Interruption or disconnection of the Remote Start/Stop or Shutdown inputs will turn off or prevent power delivered to the ACL
ignition module and turn off power to all solenoids with the exception of the Proof of Closure input. The Proof of Closure
input will only interrupt power going to the ignition module if power has not been turned on already to the ignition module. If
the system is already running, the Proof of Closure input is allowed to open during operation.
Figure 3 - Shutdown and Ignition Module(s) Power Flow Diagram
Main Power Input
The ACL CSC400 Combustion Safety Controller operates on an input voltage range between 10 and 30 Volts DC. Typical
input voltages are 12VDC and 24VDC. Whatever input voltage is delivered to the CSC400 on the Main Power Input terminals
is the same voltage delivered to the solenoid outputs. Solenoids attached to the three solenoid outputs on the CSC400 (Pilot,
Main, T/Main) need to have matching control voltages (Eg. all 12VDC or all 24VDC).
Although the CSC400 will operate with input voltages as low as 10VDC, some larger solenoid valves may not operate on such
a low voltage. For this reason, try to maintain the input voltage as close to (or slightly higher than) the required voltage for the
desired solenoids.
The Main Power Input terminals are:
Terminal Number
Description
Typical Input Values
Allowable Input Range
35
VDCIN + (positive)
12VDC or 24VDC
10 VDC (min) - 30 VDC
(max)
36
VDCIN - (negative)
0V (GND)
0V (GND)

12
The VDCIN - (negative) terminal is connected to ground internally on the CSC400 printed circuit board.
The Main power inputs (VDCIN + and VDCIN -) are protected against reverse polarity. The CSC400 will not operate if the
Main Power Input wires are reversed and it will not cause damage to the CSC400 electronics.
Bonding Ground Inputs
Extra system bonding ground terminal connections are provided.
Terminal Number
Description
Typical Input Values
Allowable Input Range
37
Ground
0V (GND)
0V (GND)
38
Ground
0V (GND)
0V (GND)
Thermocouple 1, 2, and 3 Inputs ("T/C1", "T/C2", "T/C 3")
The CSC400 controller accepts three type-K (ungrounded) thermocouples. They are clearly marked on the board for each
thermocouple and polarity (See wiring diagram "Figure 8 - CSC400 Wiring Diagram" on page 23).
Terminal
Number
Description
Temperature Range
Optional?
Thermocouple Purpose
4
T/C 1 Yellow +
-60°C to 1200°C
(-76°F to 2192°F)
TC1: No
Process temperature measurements
and solenoid control
5
T/C 1 Red -
6
T/C 2 Yellow +
-60°C to 1200°C
(-76°F to 2192°F)
TC2: Yes, but is
recommended for use as
High Temp shutdown
High-temperature shutdown for IGN1
and IGN2
7
T/C 2 Red -
8
T/C 3 Yellow +
-60°C to 1200°C
(-76°F to 2192°F)
TC3: Yes
May be used for process temperature
measurements, 4-20 Output control, or
as an auxiliary high-temp shutdown
9
T/C 3 Red -
The temperature range for each thermocouple is -60°C to 1200°C (-76°F to 2192°F).
4-20mA Level / Pressure / Temperature Inputs
The 4-20mA input terminals provide a powered 4mA to 20mA (or 1V to 5V) converter that reads a current (or voltage) input
from an external transmitter.The 4-20mA Inputs can be configured to simply provide a scaled measurement of the external
transmitter, or they can be configured to shutdown the burners if either 4-20mA input reads a value above the High Trip-point,
or below the Low Trip-point. An "Alarm only" or "Shutdown on Alarm" option is provided for each input ("SD on Alarm
Yes/No") in case the user wishes to alarm but not shut down the burners on a Low and/or High reading. The 4-20mA Inputs
may also be used with 4-20mA transmitters for setpoint control of either or both burner outputs. An OR-ing scheme is used if
both 4-20mA Inputs use setpoint control on the same burner. See the "4-20mA Input Connection Notes for Rev 1D
CSC400 Boards" section for additional details in wiring these connections.
4-20 Input
Terminal
Number
Description
Output Source for 4-20mA
Inputs
Allowable Input Range
Level
10
12/24VDC Output "+"
12 or 24VDC
Level
11
4-20mA Level Input (1) "-"
4 - 20mA, 1V - 5V
Pressure
12
12/24VDC Output "+"
12 or 24VDC
Pressure
13
4-20mA Pressure Input (2) "-"
4 - 20mA, 1V - 5V

13
4-20mA Outputs 1 and 2
The 4-20mA output terminals provide an internally-powered 4mA to 20mA converter that generates a current output
proportional to the measured temperature on either TC1, TC2, or TC3 (selectable via the menu system). An option in the menu
system allows users to select the output mode: either a direct current output directly proportional to temperature, a proportional
valve output that slowly controls an external 4-20mA valve around the selected setpoint temperature (plus or minus 5 degrees
window), or it can output either of the 4-20mA Input readings (emulating a "splitter" mode).The "splitter" mode allows for
this output to re-broadcast one of the 4-20mA Input readings to an external PLC. See the "4-20mA Output Connection
Notes for Rev 1D CSC400 boards" section for additional details in wiring these connections.
Notes:
- An output of 3.5mA means there's an error. This could mean that the selected thermocouple for the 4-20mA Output is
disabled.
4-20 Output
Terminal Number
Description
1
14
4-20mA Output 1 (mA Out) +
1
15
4-20mA Output 1 (TX) (GND) -
2
16
4-20mA Output 2 (mA Out) +
2
17
4-20mA Output 2 (I/P) (GND) -
Proof of Closure Input
The Proof of Closure Input terminals are used when a proof of closure safety shutdown valve is used in a system. If the POC
switch is open, it prevents power from being delivered to the ignition module. This safety feature eliminates the risk of
igniting a burner if the POC valve is partially open and the proof of closure switch indicates open. This is also a failsafe input
as it will not allow ignition to initiate if a wire is broken or disconnected.
These terminals must be wired to dry contacts of a remote Proof of Closure switch when used. A wire jumper must remain
across the Proof of Closure terminals when not in use.
The CSC400 LED display will flash "POC" when the Proof of Closure input is open.
Terminal Number
Description
Allowable Input Range
18
Proof of Closure
None: use dry contacts
19
Proof of Closure
None: use dry contacts
Remote Start/Stop Input
The Remote Start/Stop input allows the user to hard wire a remote switch or relay for controlling the CSC400.These terminals
must be wired to dry contacts of a remote switch or relay when used. The Remote Start/Stop switch turns on and off the power
delivered to the ignition modules as long as all other shutdowns and Proof of Closure inputs are closed and temperature values
for TC1 & TC2 (if enabled) thermocouples are within the allowable range. A wire jumper must remain across the Remote
Start/Stop terminals when not in use.
The CSC400 must have been started already for the Remote Start/Stop Input to function. The CSC400 is started by pressing
the Start button locally, or by receiving a Modbus Remote Start command.
The CSC400 LED display will show "RemStop" when the Remote Start/Stop input is open.
Terminal Number
Description
Allowable Input Range
20
Remote Start/Stop
None: use dry contacts
21
Remote Start/Stop
None: use dry contacts

14
Shutdown Inputs: High Gas, Low Gas, Level, Auxiliary 1 / 2
Opening of any switch attached to the Shutdown inputs will shut off the ignition module and de-energize all six valve outputs
(Pilot, Main, TMain for IGN1 and IGN2). If the S/D Latch menu option for any shutdown is in "Unlatched S/D" mode, the
CSC400 will attempt to restart ignition (on enabled ignitors) when any switch attached to the Shutdown inputs clears. If the
S/D Latch menu option is in "Latched S/D" mode for a selected shutdown, this set of shutdown terminals will prevent the
system from automatically restarting after it detects any interruption in continuity on these input terminals. If a latched
shutdown trips, then resets itself, the CSC400 will detect this, prevent the system from automatically restarting, and alert the
user on the LED display (and via Modbus) as to which shutdown caused the latch out.
High Gas, Low Gas (Pressure) Shutdown Input
The High Gas and Low Gas (Pressure) Shutdown inputs allow the user to hard wire a remote switch or relay for controlling the
CSC400.These terminals must be wired to dry contacts of remote gas pressure switchs or relays when used. The High/Low
Gas switch turns on and off the power delivered to the ignition module as long as all other shutdowns and Proof of Closure
inputs are closed and temperature values for TC1 & TC2 (if enabled) thermocouples are within the allowable range. A wire
jumper must remain across the High Gas Shutdown terminals when not in use. A wire jumper must remain across the Low Gas
Shutdown terminals when not in use.
The CSC400 LED display will show "High Gas" when the High Gas Shutdown input is open.
The CSC400 LED display will show "Low Gas" when the Low Gas Shutdown input is open.
Terminal Number
Description
Allowable Input Range
22
High Gas Shutdown
None: use dry contacts
23
High Gas Shutdown
None: use dry contacts
24
Low Gas Shutdown
None: use dry contacts
25
Low Gas Shutdown
None: use dry contacts
Level Shutdown Input
The Level Shutdown switch input allows the user to hard wire a remote level switch or relay for controlling the CSC400.
These terminals must be wired to dry contacts of a remote level switch (or pressure or auxiliary switch) or relay when used. If
more than one shutdown switch is used, they must be wired in series. The Level Shutdown switch controls the power delivered
to the ignition module as long as all other shutdowns and Proof of Closure inputs are closed and temperature values for both
thermocouples are within the allowable range. A wire jumper must remain across the Level Shutdown terminals when not in
use.
The CSC400 LED display will show "Level" when the Level Shutdown input is open.
Terminal Number
Description
Allowable Input Range
26
Level Shutdown
None: use dry contacts
27
Level Shutdown
None: use dry contacts
Auxiliary Shutdown 1/2 Inputs
The Auxiliary Shutdown inputs allow the user to hard wire a remote switch or relay for controlling the CSC400.These
terminals must be wired to dry contacts of a remote switch (pressure or auxiliary) or relay when used. If more than one
shutdown switch is used, they must be wired in series. The Shutdown switch turns on and off the power delivered to the

15
ignition module as long as all other shutdowns and Proof of Closure inputs are closed and temperature values for both
thermocouples are within the allowable range. A wire jumper must remain across the Shutdown terminals when not in use.
The CSC400 LED display will show "Aux 1" when the Auxiliary Shutdown 1 input is open.
The CSC400 LED display will show "Aux 2" when the Auxiliary Shutdown 2 input is open.
Terminal Number
Description
Allowable Input Range
28
Auxiliary Shutdown 1
None: use dry contacts
29
Auxiliary Shutdown 1
None: use dry contacts
30
Auxiliary Shutdown 2
None: use dry contacts
31
Auxiliary Shutdown 2
None: use dry contacts
Alarm Status Output
The Alarm Status output provides remote indication of an Alarm condition on the CSC400. When power to the CSC400 is off,
the Alarm Status contacts are open between "NO" and "COM" and closed between "NC" and "COM", indicating an Alarm
condition. The contacts are also in an Alarm condition when the CSC400 is in a shutdown state. Eg: a Shutdown switch or the
Remote Start/Stop switch is open. This provides a complete fail-safe indicator to a remote control center of the status of the
CSC400 controller.
Terminal Number
Description
Max Contact Rating
32
Alarm Status "NC"
Load current: 120mA
rms
/ mA
DC
Voltage: 30VDC, 30VP(AC)
33
Alarm Status "COM"
Load current: 120mA
rms
/ mA
DC
Voltage: 30VDC, 30V
P
(AC)
34
Alarm Status "NO"
Load current: 120mA
rms
/ mA
DC
Voltage: 30VDC, 30VP(AC)
#
Possible Alarm Conditions
1
Power is off
2
Overlay unplugged
3
Remote Start/Stop switch is open
4
High Temperature shutdown (Thermocouple 2)
5
High-Temp Latch condition
6
Shutdown switch is open (High Gas, Low Gas, Level, Aux 1, Aux 2)
7
Proof of Closure valve is open
8
Shutdown Latch condition (High Temp, High Gas, Low Gas, Level, Aux 1, Aux 2,
4-20mA Input)
9
Power Fail Latch condition
10
Short detected on solenoid valve output terminals
11
4-20mA Input Lo/Hi Shutdown enabled
12
Modbus Stop command received
13
Flame Fail (Alarm signal from ACL Ignition Module)
14
Thermocouple 1 (TC1) fault/open
15
Thermocouple 2 (TC2) fault/open (if enabled)
16
Thermocouple 3 (TC3) fault/open (if enabled)

16
AUX1 Relay & AUX2 Relay Outputs
The AUX1 & AUX2 Relays (solid state) are present to allow users to control external valves, switches, or other controls based
on thermocouple measurements or other current conditions. Both of the AUX1/AUX2 Relays are configurable to be controlled
by any of the three thermocouple's setpoints (TC1, TC2, or TC3), a custom temperature, to switch upon Flame Fail on either
ignitor, to reflect a TMain solenoid (TMain Mirror), to be on during a Purge cycle, or via Modbus control.AUX1/AUX2
Relays are turned off ("NC" is connected to "COM") when the CSC400 system is off. If a thermocouple is enabled via the
menu system, it needs to be attached to a Type-K thermocouple to operate properly. The LED Display will indicate an alarm
and the system will be turned off if there is an open fault detected with the thermocouple (if enabled).
Example: TC1 Ignitor 1 setpoint controls the dry contact AUX1 Relay switching. "NC" is connected (shorted) to "COM" if the
TC1 measurement is lower than the TC1 IGN1 setpoint temperature. "NO" is connected (shorted) to "COM" if the TC1
measurement is higher than the TC1 IGN1 setpoint temperature.
Name
Terminal
Number
Terminal Name
Mode
AUX1/2 Relay Operational Description (using TC1 and
TC3 setpoints as examples)
AUX1 Relay
39
NC - Normally
Closed
All
"NC" is connected (shorted) to "COM" if TC1 IGN1
measurement is lower than the TC1 IGN1 setpoint
temperature
AUX1 Relay
40
COM - Common
All
Common connection in both AUX1 Relay switched states
AUX1 Relay
41
NO - Normally
Open
All
"NO" is connected (shorted) to "COM" if TC1
IGN1measurement is higher than the TC1 IGN1 setpoint
temperature
AUX2 Relay
42
NC - Normally
Closed
All
"NC" is connected (shorted) to "COM" if TC3
measurement is lower than the TC3 setpoint temperature
AUX2 Relay
43
COM - Common
All
Common connection in both AUX2 Relay switched states
AUX2 Relay
44
NO - Normally
Open
All
"NO" is connected (shorted) to "COM" if TC3
measurement is higher than the TC3 setpoint temperature
Note: Both of the AUX1/2 Relays are configurable to be controlled by any of the three thermocouples: TC1, TC2, or
TC3 and may also have a custom setpoint temperature set as its switching point. Either relay may also be
configured to switch upon Flame Fail on either Ignitor or upon Modbus command, or other options. Both AUX
relays will turn off (connecting NC to COM) upon a shutdown.
Modbus / RS485 Communication Connections
The three Modbus/RS485 terminals are used for connecting the CSC400 Controller to a Modbus communications channel. The
CSC400 Controller is a Modbus Slave Device that implements the Modbus RTU protocol on an RS-485, half-duplex, physical
connection. The default Modbus communication parameters are 9600 baud, 8 data bits, no parity bits, one stop bit (“8N1”),
Modbus Slave ID (Modbus address) 2.
The RS485 signal naming convention used in this document and by many RS485 transceiver vendors is reversed from what the
EIA/TIA-485 specification states:
CSC400 Modbus/RS485
Documentation
EIA/TIA-485
Naming Convention
Modbus
Specification
Name
Description
A (“RS485 A +” or "D0 A+")
B
D1
Non-Inverting, Transceiver
Terminal 1, V1 voltage (V1 > V0
for binary 1 (OFF) state

17
B (“RS485 B –” or "D1 B-")
A
D0
Inverting, Transceiver Terminal
0, V0 voltage (V0 > V1 for binary
0 (ON) state
Isolated GND (or common
GND)
C
Common
Signal and Optional Power
Supply common ground
Due to the potential for large amounts of noise on the Modbus communication cable, the “Isolated Ground” terminal is
connected to earth ground on the CSC400 board to improve noise immunity.
Ignition Module 1 and 2 Inputs & Outputs
The four terminals marked as "To Igniter 1" on the main circuit board need to be wired directly to the ACL Ignition Module if
Ignitor 1 is enabled in the menu system. The four terminals marked as "To Igniter 2" on the main circuit board need to be
wired directly to the ACL Ignition Module if Ignitor 2 is enabled in the menu system. This provides two-way communication
between the CSC400 and the ignition module(s), creating a complete combustion safety control and burner ignition system.
(See wiring diagram).
As shown in the Ignition Module Power Flow Diagram above, the "P"ower outputs to the ignition modules can be interrupted
by eleven methods (shutdowns, on/off switches, temperature relays, solid-state control relays).
Due to the fact that the two ignitors are independently controlled, a disabled ignitor does not need to have a jumper installed
between the "P" and "V" terminals to ensure that the enabled ignitor still works.
All of the below signals need to be attached between the CSC400 and Ignition Module 1 for the burner system to work
properly when Ignitor 1 is enabled.The Pilot GND signal is used to connect the ground wire attached to the Pilot assembly
ground lug to the ground of the CSC400.
"IGN 1"
Terminal
Number
Designation
Description
Ignition Module
Wiring Harness
Color
Direction
58
P
Power (12VDC)
Red
Power output to Ignition
Module
59
A
Alarm
Blue
Input signal from Ignition
Module (12VDC level)
60
V
Valve
Brown
Input signal from Ignition
Module (12VDC level)
61
GND
Ground
Yellow
Ground
62
Pilot GND
Ground to Pilot
Ground lug
connection
N/A
Ground
All of the below signals need to be attached between the CSC400 and Ignition Module 2 for the burner system to work
properly when Ignitor 2 is enabled. The Pilot GND signal is used to connect the ground wire attached to the Pilot assembly
groung lug to the ground of the CSC400.
Refer to the "Modbus/RS-485 Cable Connections – Field Installations" section on page 39
or the document "CSC400_Modbus_Installation_Manual.pdf" for more details on additional
Modbus registers, programming, testing, and troubleshooting.

18
"IGN 2"
Terminal
Number
Designation
Description
Ignition Module
Wiring Harness
Color
Direction
47
P
Power (12VDC)
Red
Power output to Ignition
Module
48
A
Alarm
Blue
Input signal from Ignition
Module (12VDC level)
49
V
Valve
Brown
Input signal from Ignition
Module (12VDC level)
50
GND
Ground
Yellow
Ground
51
Pilot GND
Ground to Pilot
Ground lug
connection
N/A
Ground
Solenoid Output Connections, Ignitor 1 and 2
The solenoid output connections are designed for driving external solenoid valves. Each output is rated for a maximum of 3A
of steady-state current output. The main input voltage (either 12VDC or 24VDC) is fused and then directed through solid-state
relays which controls this voltage output to each solenoid terminal. The solid-state relays are able to detect direct shorts and
elevated current levels on solenoid outputs and shut down the affected solenoid outputs.
Note: All solenoid outputs can be configured to use separate Low Power Solenoid settings. Therefore, the setting for each
solenoid output must be verified to work with the attached solenoid. Larger solenoids with higher power requirements will
need to be set to a higher setting (40% or 50%) to remain open when desired. Smaller solenoids (Pilot valves) should be able
to work on a setting down to 10% - 20%. A lower solenoid driver setting means more power savings.
The solenoid output connections are matched with their corresponding Ignition module, as shown in the following table:
"IGN 1" Solenoid
Terminal Number
Ignitor
Block
Designation
Solenoid Output Description
63
IGN 1
T/Main +
Temperature Main +
64
IGN 1
T/Main -
Temperature Main - (GND)
65
IGN 1
Main +
Main +
66
IGN 1
Main -
Main - (GND)
67
IGN 1
Pilot +
Pilot +
68
IGN 1
Pilot -
Pilot - (GND)
"IGN 2" Solenoid
Terminal Number
Ignitor
Block
Designation
Description
52
IGN 2
T/Main +
Temperature Main +
53
IGN 2
T/Main -
Temperature Main - (GND)
54
IGN 2
Main +
Main +
55
IGN 2
Main -
Main - (GND)
56
IGN 2
Pilot +
Pilot +
57
IGN 2
Pilot -
Pilot - (GND)

19
Pilot Solenoid
The Pilot Solenoid terminals provide power to the Pilot Solenoid valve. The Pilot valve allows gas to flow through the pilot
valve train for initial ignition and flame sensing. During normal operation, the CSC400 turns on the pilot solenoid first while
attempting to light the pilot flame via the ignition module. The pilot's flame needs to be stable before the Main and T/Main
solenoid outputs are turned on.
This output has a low power solenoid feature provided by an onboard solenoid driver circuit. This circuit can reduce power
consumption of the solenoids by as much as 80%. This circuit also helps eliminate any noise that may be produced by some
solenoids, and helps extend the life of the solenoids.
For more information on the Low Power Solenoid Driver, see the Low Power Solenoid Drivers section on page 19.
Main Solenoid
The Main Solenoid terminals provide power to the Main Solenoid valve. Power to these terminals is present a minimum of 10
seconds (adjustable to 120s max) after the pilot's flame is detected and the shutdowns are satisfied.
The Main Solenoid output also has the same low power solenoid feature provided by an onboard solenoid driver circuit. For
more information on the Low Power Solenoid Driver, see the Low Power Solenoid Drivers section on page 19.
T/Main Solenoid (Process Temperature Control Valve)
The Temperature Main ("T/Main" or "TMain") Solenoid terminals provide power to the T/Main solenoid valve for process
temperature control. Power to these terminals is present a minimum of 10 seconds (adjustable to 120s max) after the pilot's
flame is detected and the shutdowns are satisfied. The T/Main solenoid valve is also controlled by the measured temperature
on Thermocouple 1 (TC1). This allows for individual temperature control of one of the main solenoids (T/Main), eliminating
unnecessary stroking of the main safety shutdown valves to control main gas to the burner.
The T/Main Solenoid output also has the same low power solenoid feature provided by an onboard solenoid driver circuit. For
more information on the Low Power Solenoid Driver, see the Low Power Solenoid Drivers section on page 19.
Low Power Solenoid Drivers
The Low Power Solenoid Drivers are individual control circuits added to each solenoid output that saves power drawn by the
solenoid by altering the cycle time power is delivered to the solenoid once it is driven fully on. Larger solenoids require more
power to keep them open, therefore needing a larger cycle time (eg: 40%). The cycle time percentage is shown in the Solenoid
Drivers menu section: 100% means the solenoid is driven without any power savings, 10% cycle time means that the maximum
power savings for the selected solenoid is utilized. The setting for each solenoid output must be verified to work with the
attached solenoid.

20
CSC400 Front Panel Buttons and LED Display
The CSC400 Controller provides a simple status and control interface to the user on the overlay mounted on the outside of the
CSC400's box. A 4-line, 20-character LED display provide temperature status, 4-20mA input levels, and shutdown status and
feedback while six membrane push buttons provide control for setting temperature setpoints, selecting menu options, and
configuring the CSC400.
After configuring options and setting the setpoints, pressing the Menu key will go back to the Main Screen of the display,
showing the actual thermocouple temperature readings. The measured temperatures and the setpoint displayed are
configurable in the menu settings but the default settings show a typical profile: TC1 and TC2 displayed with setpoints and
IGN1 enabled with IGN1's solenoid output status.
The display will show "Disab" when thermocouples are not enabled through the menu system.
The display will show "OPEN" if the thermocouples are not connected or if they have failed in an open condition.
Figure 4 - CSC400 Controller Front Panel Overlay
#
Overlay Button /
Display
Mode
Description
OLED Display:
4-Lines, 20
characters per line
All
The LED display shows the temperature for thermocouples 1, 2, and 3,
any selected 4-20mA input levels, and provides a variety of shutdown
and solenoid status messages to the user.
The information displayed per line is user configurable. For example, any
of three thermocouples can be displayed, solenoid status of either Ignitor,
and 4-20mA input values.