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C910-485 Heat Trace Controller
INSTALLATION, OPERATION AND
MAINTENANCE MANUAL
Firmware versions up to V4.0X
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CONTENTS
Section 1 Overview ......................................................................................................................... 3
1.1 Introduction .......................................................................................................................... 3
1.2 Product Overview ................................................................................................................. 3
1.2.1 Description .................................................................................................................. 3
1.2.2 Features ...................................................................................................................... 3
1.3 Product Specification .......................................................................................................... 5
Section 2 Installation and Wiring ..................................................................................................... 8
2.1 Introduction .......................................................................................................................... 8
2.2 Initial Inspection ................................................................................................................... 8
2.3 Installation Location ............................................................................................................ 8
2.4 Mounting Procedures .......................................................................................................... 8
2.5 Wiring .................................................................................................................................... 9
2.5.1 Power Connections .................................................................................................... 9
2.5.2 Temperature Sensor and Extension Cables ........................................................... 10
2.5.3 External Device Control/Override ............................................................................ 10
2.6 Alarm Relay Connections .................................................................................................. 10
2.6.1 Communication Signal Connections ...................................................................... 12
2.7 Initializing the Controller .................................................................................................... 13
2.7.1 Initial Heating Cable Test ......................................................................................... 13
Section 3 Operator Console .......................................................................................................... 14
3.1 Alphanumeric Display ........................................................................................................ 14
3.2 Keypad ................................................................................................................................ 14
3.3 LED Indicators .................................................................................................................... 15
Section 4 C910-485 Operation ...................................................................................................... 16
4.1 Operating Modes ................................................................................................................ 16
4.1.1 Four Modes of Console............................................................................................ 16
4.2 Console Mode Menus ........................................................................................................ 18
4.2.1 Alphanumeric Tag Assignment ............................................................................... 19
4.2.2 Setting Units ............................................................................................................. 20
4.2.3 Switch Control Mode ................................................................................................ 21
4.2.4 Control Setpoint........................................................................................................ 22
4.2.5 Deadband .................................................................................................................. 23
4.2.6 Proportional Ambient Sensing Control (PASC) ...................................................... 24
4.2.7 Low Temperature Alarm: Enable (Lo TS 1 and Lo TS 2) ....................................... 25
4.2.8 Low Temperature Alarm: Setting (Lo TS 1 and Lo TS 2) ....................................... 26
4.2.9 High Temperature Alarm: Enable (Hi TS 1 and Hi TS 2) ........................................ 27
4.2.10 High Temperature Alarm: Setting (Hi TS 1 and Hi TS 2) ..................................... 28
4.2.11 Temperature Sensor Failure Alarm ....................................................................... 29
4.2.12 High Temperature Cut-out, Setpoint and Alarm (HI Limit TS1/HI limitTS2) ...... 30
4.2.13 Low Load Current Alarm: Enable (Lo Load) ......................................................... 31
4.2.14 Low Load Current Alarm: Setting (Lo Load) ......................................................... 32
4.2.15 Factory Default Settings (Load Defaults) ............................................................. 33
4.2.16 Ground-fault Current Alarm level (Hi GF Alarm) ................................................... 34
4.2.17 Ground-fault Current Trip Level (Hi GF Trip) ........................................................ 35
4.2.18 Temperature Sensor Failure Mode ....................................................................... 36
4.2.19 Temperature Sensor Control Mode (TS CLT Mode) ............................................ 37
4.2.20 External Input: Inhibit or Force on. ....................................................................... 38
4.2.21 Firmware Version ................................................................................................... 39
4.2.22 Passcode ................................................................................................................ 40
4.2.23 Communications Setup ......................................................................................... 41
4.2.24 Auto-Cycle: Enabling .............................................................................................. 43
4.2.25 Auto-Cycle: Interval ................................................................................................ 44
4.2.26 Auto-Cycle: Units .................................................................................................... 45
4.2.27 Contactor Count ..................................................................................................... 46
4.2.28 Monitor and Maintenance Menus ......................................................................... 47
4.2.29 Acknowledging and Resetting Alarms .................................................................. 49
4.2.30 Alarm Output Normal State ................................................................................... 50
Section 5 Troubleshooting ............................................................................................................ 51
Section 6 Appendix A: Proportional Ambient Sensing Control (PASC) ........................................... 53
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OVERVIEW Section 1
1.1 INTRODUCTION
This manual provides information pertaining to the installation, operation, testing and
maintenance of the nVent RAYCHEM C910-485 Heat Trace Controller.
Additional copies of this user manual may be ordered separately through your nVent
representative or online at nVent.com
This document covers the C910-485 Heat Trace Controller and its available options. To
ensure that you are using the correct documentation for your particular version of
controller, please check the firmware version number of your C910-485 against the
version number listed on the front of this manual. This may be displayed using the
operator console or a communicating device.
1.2 PRODUCT OVERVIEW
1.2.1 Description
The C910-485 Electronic Heat Trace Controller controls, monitors, and communicates
alarms and data for one heating cable circuit. It comes with a RS-485 communication
module for remote operation over Modbus® protocol or in conjunction with the nVent
RAYCHEM ACS-30 control system, if desired.
1.2.2 Features
A detailed description of available features may be found in Section 4 of this manual.
Highlights of specific features follow:
Keypad and Alphanumeric Display
A six character alphanumeric LED display provides the operator with large easy to read
messages and prompts, eliminating complex and cryptic programming. Six individual
keys are provided to quickly access alarming and operational information.
–40°F to 140°F (–40°C to 60°C) Operation
Extended temperature operation permits installation in all but the harshest environments.
Single or Dual Temperature Sensor Inputs
The ability to utilize one or two temperature sensor (TS) inputs allows the selection of
one of eight control modes and programming of all temperature parameters.
High and Low Temperature Alarms
High and low temperature alarms are offered for both temperature sensor inputs of each
control point.
High Temperature Cut-out
High temperature cut-out is provided for both temperature sensor inputs.
Low Current Alarms
The C910-485 offers adjustment of the low alarm points over the entire current
measurement range.
Electromechanical Relay (EMR) Output
The C910-485 is equipped with a 30-A rated electromechanical relay (EMR) output switch
with device failure alarm.
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Ground-fault Alarm and Trip
Ground-fault (GF) current levels are monitored and are displayed in milliamperes. The
adjustable ground-fault level gives the user the choice of both alarm and trip levels
suitable for the particular installation.
Proportional Ambient Sensing Control (PASC)
The C910-485 includes the Proportional Ambient Sensing Control (PASC) mode to
maximize the energy efficiency of the heat tracing system.
Minimum/Maximum Temperature Tracking
The controller maintains the minimum and maximum temperature values measured
since the last reset of these values.
Temperature Alarms
The controller alarms on user selectable low and high temperature limits.
Auto-cycling
The controller will momentarily energize the circuit (for 10 seconds) at a programmable
interval in order to test the heat tracing circuit during periods of non-use. This feature will
detect issues with the heat-tracing circuit before it can lead to system damage.
Temperature Sensor Failure Alarm
Both open and shorted sensors are detected and alarmed by the controller.
Full Digital Communications
The C910-485 incorporates RS-485 serial communication for applications requiring direct
interfacing to BMS systems using Modbus protocol or used as a single circuit extension
to the ACS-30 control system.
Certification
nVent certifies that this product met its published specifications at the time of shipment
from the factory.
Limited Warranty
This nVent product is warranted against defects in material and workmanship for a
period of 18 months from the date of installation or 24 months from the date of
purchase, whichever occurs first. During the warranty period, nVent will, at its option,
either repair or replace products that prove to be defective. For warranty service or repair,
this product must be returned to a service facility designated by nVent. The Buyer shall
prepay shipping charges to nVent and nVent shall pay shipping charges to return the
product to the Buyer. However, the Buyer shall pay all shipping charges, duties, and taxes
for products returned to nVent from another country. nVent warrants that the software
and firmware designated by nVent for use with the C910-485 Controller will execute its
programming instructions properly. nVent does not warrant that the operation of the
hardware, or software, or firmware will be uninterrupted or error-free.
Warranty Exclusion/Disclaimer
The foregoing warranty shall not apply to defects resulting from improper or inadequate
maintenance by the Buyer, Buyer-supplied software or interfacing, unauthorized
modification or misuse, operation outside of the specifications for the product, or
improper installation. No other warranty is expressed or implied. nVent disclaims the
implied warranties of merchantability and fitness for a particular purpose.
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Exclusive Remedies
The remedies provided herein are the buyer’s sole and exclusive remedies. nVent shall
not be liable for any direct, indirect, special, incidental, or consequential damages,
whether based on contract, tort, or any other legal theory.
Conducted and Radiated Emissions—FCC/DOC Statement of Compliance
This equipment has been tested and found to comply with the limits for a Class A digital
device, pursuant to Part 15 of the FCC rules. These limits are designed to provide
reasonable protection against harmful interference when the equipment is operated in a
commercial environment. This equipment generates, uses, and can radiate radio
frequency energy and, if not installed and used in accordance with the instruction
manual, may cause harmful interference to radio communications. Operation of this
equipment in a residential area is likely to cause harmful interference, in which case the
user will be required to correct the interference at their expense. This equipment does not
exceed Class A limits for radio emissions as set out in Schedule V to VIII of the Radio
Interference Regulations of Communication Canada.
1.3 PRODUCT SPECIFICATION
General
Area of use
Nonhazardous locations
Approvals
Supply voltage
100 V to 277 V, +5/–10%, 50/60 Hz
Common supply for controller and heat
-tracing circuit
Enclosure
Protection
NEMA 4X
Materials
FRP/Polycarbonate
Ambient operating temperature
range
–40°F to 140°F (–40°C to 60°C)
Ambient storage temperature
range
–40°F to 185°F (–40°C to 85°C)
Relative humidity
0% to 90%, noncondensing
Control
Relay type
Double-pole, mechanical
Voltage, maximum
277 V nominal, 50/60 Hz
Current, maximum
30 A @ 104°F (40°C) derated to 20 A @ 140°F (60°C)
Control algorithms
EMR: On/off, proportional ambient sensing control
(PASC)
Control range
0°F to 200°F (–18°C to 93°C)
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Monitoring
Temperature
Low alarm range 0°F to 180°F (–18°C to 82°C) or OFF
High alarm range
0°F to 200°F (–18°C to 93°C) or OFF
Ground fault
Alarm range 20 mA to 100 mA
Trip range
20 mA to 100 mA
Current
Low alarm range 0.3 A to 30 A or OFF
Autocycle
Diagnostic test interval adjustable from 1 to 240 minutes
or 1 to 240 hours
Temperature Sensor Inputs
Quantity
Two inputs standard
Types
100 Ω platinum RTD, 3-wire, α= 0.00385 ohms/ohm/°C
Can be extended with a 3-conductor shielded cable of 20
Ω
maximum per conductor
Alarm Outputs
AC relay
Isolated solid-state triac, SPST, 0.75 A maximum, 100 V
to 277 V nominal
Dry contact relay
Pilot duty only, 48 V/dc, 500 mA maximum, 10 VA
maximum resistive switching
Note: Outputs are configurable as “open on alarm” or “close on alarm”
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Programming and Setting
Method
Programmable keypad, or ACS-30 user interface network
Units
Imperial (°F, in.) or Metric (°C, mm)
Digital display
Actual temperature, control temperature, heating cable
current, ground fault, programming parameter values,
alarm values
LEDs
Current mode, heating cable on, alarm condition,
receive/transmit data
Memory
Nonvolatile, restored after power loss, checksum data
checking
Stored parameters (measured)
Minimum and maximum temperature, maximum groundfault current, maximum heating cable current, contactor
cycle count, time in use
Alarm conditions
Low/high temperature, low current
Ground
-fault alarm, trip
RTD failure, loss of programmed values, or EMR failure
Other
Password protection
Connection Terminals
Power supply input
Screw terminals, 22–8 AWG
Heating cable output
Screw terminals, 22–8 AWG
Ground
Two box lugs, 14–6 AWG
RTD/alarm/communications
28–12 AWG spring clamp terminals
Mounting
FRP/Poly carbonate enclosure
Surface mounting with four fixing holes on 7.25 in x 11.7
in (
184 mm x 297 mm) centers
Hole diameter: 0.31 in
(8 mm)
Communications
Protocol
Modbus RTU / ASCII
Topology
Multidrop, daisy chain
Cable
Single shielded twisted pair, 26 AWG or larger
Length
4,000 ft. (1.3 km) maximum @ 9600 baud
Quantity
Up to 32 devices without repeater
Address
Programmable
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INSTALLATION AND WIRING Section 2
2.1 INTRODUCTION
This section includes information regarding the initial inspection, preparation for use, and
storage instructions for the C910-485 Heat Trace controllers.
2.2 INITIAL INSPECTION
Inspect the shipping container for damage. If the shipping container or cushioning
material is damaged, it should be kept until the contents of the shipment have been
verified and the equipment has been checked mechanically and electrically. If the
shipment is incomplete, there is mechanical damage, a defect, or the controller does not
pass the electrical performance tests, notify the nearest nVent representative. If the
shipping container is damaged, or the cushioning material shows signs of stress, notify
the carrier as well as your nVent representative. Keep the shipping materials for the
carrier’s inspection.
2.3 INSTALLATION LOCATION
The wide ambient operating temperature range of the controller permits installation in
most locations. Considerations should include accessibility for maintenance and testing
and the location of existing conduits.
2.4 MOUNTING PROCEDURES
The mounting template is shown in Figure 2.1.
Drill conduit entry holes prior to mounting. Conduit entries should be made in the bottom of
the enclosure if possible to reduce the possibility of water entry from condensation or
leakage. Conduit entries must be drilled or punched using standard industry practices. Use
bushings suitable for the environment and install such that the completed installation remains
waterproof. Grounding hubs and conductors must be installed in accordance with Article 250
of the National Electrical Code and Part I of the Canadian Electrical Code.
Figure 2.1 – Mounting Hole Template
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2.5 WIRING
The following drawings provide sample wiring diagrams for the C910-485 control products
and optional accessories. Refer to Figure 2.2 for wiring terminal locations. Please contact
your local nVent representative for information regarding other available options.
Figure 2.2 – Power Connection
2.5.1 Power Connections
The C910-485 controller may be powered directly from a 100 V to 277 V supply.
All of the power terminals are labeled for easy identification. Do not attempt to use wire
sizes that exceed the marked terminal ratings and avoid terminating two wires on the
same terminal whenever possible.
Note: Make sure that power terminals are retightened several days after installation.
Stranded wire will tend to compress when initially installed; therefore, these terminals
should be checked for tightness several times after the system is installed to ensure that
a good connection is maintained.
Note: Follow the industry standard grounding practices. Do not rely on conduit
connections to provide a suitable ground. Grounding terminals/screws are provided for
connection of system ground leads.
Figure 2.3 – Power Connection
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2.5.2 Temperature Sensor and Extension Cables
The C910-485 has two (2) RTD inputs. Use only 3-wire 100 Ω Platinum RTDs (DIN 43760,
α= 0.00385 Ω/ Ω/°C)
Note: The RAYCHEM C910-485 default is set for one RTD in position one. If a second
RTD is installed in position two, the controller must be power cycled to recognize the
RTD.
Figure 2.4 – Temperature Sensor Wiring
Use shielded, twisted, three-conductor wire for the extension of RTD leads. The wire size
should ensure that the maximum allowable lead resistance is not exceeded (20 Ω/lead).
RTD wiring should be grounded at the controller end only, using the terminals provided.
2.5.3 External Device Control/Override
The C910-485 controller can be forced on or off using an external device with a dry
contact.
Figure 2.5 – Wiring for External Device Control/Override
2.6 ALARM RELAY CONNECTIONS
Two types of alarm relays are provided: One is a DC contact and can be connected as dry
contact (Fig. 2.6) or as a 12 Vdc contact (Figure 2.7). The second is an AC relay (triac)
and can be connected as an alarm relay (Figure 2.8) or a powered alarm relay (Figure
2.9). Both may be programmed for normally open (N.O.) or normally closed (N.C.)
operation.
Note: Both alarm relays are controlled by the C910-485 using the same signal.
Note: The dry contact alarm relay is intended to be used for switching low-voltage, low-
current signals. Do not use this relay to directly switch line voltages.
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Alarm Output Wiring
Figure 2.6 – Used As a Dry Contact
Figure 2.7 – Used As a Switched DC Contact
Figure 2.8 – Used As an AC Alarm Relay
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Figure 2.-9 – Used As a Powered AC Alarm Relay
Figure 2.10 – Used As an AC Alarm Relay
Figure 2.11 – Used as a Powered AC Alarm Relay
2.6.1 Communication Signal Connections
The C910-485 controller includes a RS-485 communications interface. Use twisted pair,
shielded cable communication wiring. Ground the shield on communications wiring at
one end only, using the terminals provided.
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Figure 2.12 – Communication Wiring (C910-485 only) RS-485 (2-Wire) Connections
2.7 INITIALIZING THE CONTROLLER
2.7.1 Initial Heating Cable Test
To minimize the risk of damage to the controller due to a heating cable fault, the integrity
of the heating cable should be verified by performing the commissioning tests detailed in
the appropriate product installation and operating manual. These manuals can be found
on nVent.com
These tests must be performed with the controller output disconnected. Once the cable
has been checked, it may be reconnected to the controller and power applied.
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OPERATOR CONSOLE Section 3
3.1 ALPHANUMERIC DISPLAY
The console incorporates a six characters, fourteen segment, plus decimal LED display.
Messages and prompts that are greater than six characters long are scrolled, allowing
more meaningful, non-cryptic messages to be used.
3.2 KEYPAD
The local keypad consists of six keys that allow you to select the console mode function
that you are interested in. For certain keys, the SHIFT key selects an alternate function, as
shown by the text above that key. When connected to the ACS-30 control system, the key
pad is locked out and will display "Remote Control".
Figure 3.1 – Keypad
Key
Function
SHIFT
Press to activate a
shifted function; the next key pressed uses the
alternate (shifted)
function (ALARM, MONITOR and CONFIG).
The SHIFT LED illuminates, indicating the next key uses the alternate
(shifted) function
.
Pressing SHIFT again cancels the alternate (shifted) function.
TEST
Turns on heating cable circuit for 30 seconds
.
SHIFT + TEST Switches the console to the Alarm/reset mode.
BACK
Exits the current menu (or cancels the new
setting when editing a
parameter)
Moves the cursor to the left when editing an alphanumeric
parameter
.
[SHIFT + MONITOR] Switches the console to the Monitor mode.
ENTER
Selects the item in the display (or accepts the setting when editing a
parameter).
Moves the cursor to the right when editing an alphanumeric
parameter.
[shift + CONFIG] Switches the console to the CONFIG mode.
Moves to the previous item in a
menu.
Increments the value when editing.
Moves to the next item in a menu.
Decrements the value when editing.
Up/Down Arrow
Keys
Once the main menu has been entered, use the Up/down arrow keys
to navigate the program options.
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3.3 LED INDICATORS
The console includes eight LED indicators:
Four LEDs indicate the console operating mode (SHIFTed function, ALARM, MONITOR, or
CONFIGure modes).
Two status LEDs indicate the alarm and control output status of the controller:
The OUTPUT LED, when illuminated steadily, indicates that the output of the
controller is turned on and is allowing current to flow into the heating cable circuit.
The ALARM LED will flash (approximately once per second) when the controller has
detected an alarm condition.
Two additional LEDs are used to indicate external communications activity and are only
used with the C910-485 with the optional RS-485 communications interface.
The “Rx” LED flashes to show that the Controller is receiving information via its
communications port.
The “Tx” LED flashes when the Controller is transmitting information via its
communications port.
Figure 3.2 – Operator Console
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C910-485 OPERATION Section 4
4.1 OPERATING MODES
4.1.1 Four Modes on Console
Scan
This is the default mode displayed during normal operation. In this mode, the console
sequentially displays load current, temperature, and setpoint readings.
Alarm
This mode allows you to examine or reset any alarms that may exist. The LED above the
ALARM key is illuminated while in this mode. To enter this mode:
Monitor
This mode allows you to examine any of the controller readings such as temperature,
load current, etc. The LED above the MONITOR key is illuminated while in this mode. To
active this mode:
Configure
This mode allows you to access the console menus to examine or alter the settings. The
LED above the CONFIG key is illuminated while in this mode. To access the operational
menus:
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4.2 CONSOLE MODE MENUS
The Console Mode Menu Index below shows all user interface parameters. This menu
shows the Factory Default along with the associated range. The section column refers to
the section in this manual that illustrates the actual keystrokes required to input the
parameters.
Menu #
Section
Menu
Defaults
1
4.2.1
Tag =
00261439
2
4.2.2
Units =
Imperial
3
4.2.3
Switch Control Mode
ON /OFF
4
4.2.4
Control Setpoint =
40’F 5 4.2.5
Deadband =
5’F 6 4.2.6
PASC Setup
… 7 4.2.7
LO TS 1 = LO TS 2 =
DIS 8 4.2.8
LO TS 1 = LO TS 2 =
35’F 9 4.2.9
HI TS 1 = HI TS 2 =
DIS
10
4.2.10
HI TS 1 = HI TS 2 =
180‘F
11
4.2.11
TS 2 Fail =
DIS
12
4.2.12
TS 1 HI LIMIT = TS 2 HI LIMIT =
TS 1 HI LIMIT Setpoint = TS 2 HI LIMIT Setpoint =
TS 1 HI LIMI Alarm = TS 2 HI LIMI Alarm =
DIS
200’F
DIS 13
4.2.13
LO Load =
ENA
14
4.2.14
LO Load =
1.0 A
15
4.2.15
Load Defaults
No
16
4.2.16
HI GFI =
20 mA
17
4.2.17
GFI Trip =
30 mA
18
4.2.18
TS Fail Mode =
ON
19
4.2.19
TS CTL Mode =
TS 1 – FAIL ON
20
4.2.20
OVERRIDE Source =
Ext.
Input =
Remote
Not Used
21
4.2.21
Version
V4.04.3
22
4.2.22
Passcode =
0
23
4.2.23
Communication Setup
HTCbus
24
4.2.24
Auto-Cycle =
DIS
25
4.2.25
Auto-Cycle Interval =
8
26
4.2.26
Auto-Cycle Units =
Hours
27
4.2.27
Contactor Count =
200000
28
4.2.28
Alarm Output =
N.C.
29
4.2.29
Acknowledging/Resetting Alarms
N/A
30
4.2.30
Alarm Output Normal State
Normally Closed
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4.2.1 Alphanumeric Tag Assignment
Purpose A 19 character alphanumeric TAG may be assigned to a control point
to allow it to be easily associated with a pipe, vessel, process, circuit,
drawing name, or number.
Setting
Any combination of 19 characters from A–Z, 0–9, /, -, ., (, ), or #.
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4.2.2 Setting Units
Purpose
This allows selection of the type units (temperature or size) to display on
the
operator.
Setting
Metric or Imperial
Factory Default
Imperial
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4.2.3 Switch Control Mode
Purpose
This allows selection of the type of algorithm to be used to maintain the
control setpoint
temperature. Reference Figure 2.5 for the External Direct
wiring schematic.)
Setting
On/Off or Proportional Ambient
Sensing Control (PASC)
, External
Direct
Factory Default
On/off
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4.2.4 Control Setpoint
Purpose
This is the temperature that the controller uses to determine whether its
output switch should be on or off.
Setting/Range
0°F to 200°F (–18°C to 93°C)
Factory Default
40°F (4°C)
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4.2.5 Deadband
Purpose
The deadband is a window of difference between the measured
control temperature and the desired
control setpoint temperature
and provides the decision to turn the output off or on
Setting/Range
1°F to 10°F (1°C to 6°C)
Factory Default
5°F (3°C)
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4.2.6 Proportional Ambient Sensing Control (PASC)
Purpose
This control mode sets Proportional Ambient Sensing Control (PASC). See
Appendix A for more details.
Setting
Range
Factory Default
Pipe Size (inch):
½, 1 or, ≥ 2
½- Control Setpoint:
0 to 200°F (–18 to 92°C)
40°F (4°C)
Min. Design Ambient:
–99 to 125°F (–73 to 52°C)
–40°F (–40°C)
Power Adjust Factor:
10 – 200%
100%
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4.2.7 Low Temperature Alarm: Enable (Lo TS 1 and Lo TS 2)
Purpose
This allows the user to enable or disable the low temperature alarm for
temperature sensor number 1 and 2.
Alarm time delay filter is factory set at 15 minutes.
Setting/Range
Enable or disable
Factory Default
Enable
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4.2.8 Low Temperature Alarm: Setting (Lo TS 1 and Lo TS 2)
Purpose
This allows the user to set the low temperature alarm setting for
temperature sensor number 1 and 2.
Alarm time delay filter is factory set at 15 minutes.
Setting/Range
0°F to 180°F (–18 to 82°C)
Factory Default
35°F (2°C)
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4.2.9 High Temperature Alarm: Enable (Hi TS 1 and Hi TS 2)
Purpose
This allows the user to enable or disable the high temperature alarm
for temperature sensor number 1 and 2. When enabled, high limit
cutout feature will force the controller output off if the
temperature
reading exceeds the HIGH
ALARM temperature setting. This is a non-
latching condition, so once the reading drops below the HIGH
temperature ALARM
setting, the controller will resume normal
operation.
Alarm time delay filter is factory set at 15 minutes.
Setting/Range
Enable or disable
Factory Default
Disable
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4.2.10 High Temperature Alarm: Setting (Hi TS 1 and Hi TS 2)
Purpose
This allows the user to set the high temperature alarm Setting for
temperature sensor number 1 and 2.
Alarm time delay filter is factory set at 15 minutes.
Setting/Range
0°F to 200°F (–18° to 93°C)
Factory Default
180°F (82°C)
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4.2.11 Temperature Sensor Failure Alarm
Purpose
This allows the user to enable or disable the temperature sensor
failure alarm.
Alarm time delay filter is factory set < 2 minutes.
Setting/Range
Enable or disable
Factory Default
Disable
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4.2.12 High Temperature Cut-out, Setpoint and Alarm
(HI Limit TS1/HI limitTS2)
Purpose
Set high temperature alarm and cut-out values.
Settings/Ranges:
Enable/Disable HI Limit
Set point: 0°F (-18°C) to 200°F (93°C)
Enable/Disable Alarm
Factory Defaults:
Disable
200°F (93°C)
Disable
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4.2.13 Low Load Current Alarm: Enable (Lo Load)
Purpose
This allows the user to enable or disable the low load current alarm
to detect
current levels which are lower than a preset limit for the
application.
Alarm time delay filter is factory set at < 2 minutes.
Setting/Range
Enable or disable
Factory Default
Enable
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4.2.14 Low Load Current Alarm: Setting (Lo Load)
Purpose
This allows the user to set the low load current alarm level.
Alarm time delay filter is factory set at < 2 minutes.
Setting/Range
0.3 A to 30 A or off
Factory Default
1 A
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4.2.15 Factory Default Settings (Load Defaults)
Purpose
To provide a quick method of re-Setting the controller’s configuration
parameters to the
Factory Default parameters.
Setting
N/A
Factory Default
N/A
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4.2.16 Ground-fault Current Alarm level (Hi GF Alarm)
Purpose
This allows the user to set the ground-fault current alarm level.
Exceeding this limit will trigger the
alarm to indicate that a ground-
fault condition exists
in the heating cable circuit. To protect against
the risk of fire or shock, ground
-fault level should be set at the lowest
level possibl
e to allow normal operation of the cable.
Alarm time delay filter is factory set as immediate
Setting/Range
20 mA to 100 mA
Factory Default
20 mA
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4.2.17 Ground-fault Current Trip Level (Hi GF Trip)
Purpose
This allows the user to set the ground-fault current trip level.
Exceeding this limit will result in the output switch being latched off
and the G
round-fault Level Trip Alarm activated to indicate a ground
fault condition.
WARNING: Fire Hazard. Ground-fault trip alarms must not be
ignored. To
prevent the risk of fire, do not re-energize heating cables
until the fault is identified and corrected.
Alarm time delay filter is factory set as immediate
Setting/Range
20 mA to 100 mA
Factory Default
30 mA
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4.2.18 Temperature Sensor Failure Mode
Purpose
This mode sets the controller to turn the output switch ON or OFF if
all selected temperature sensors fail.
Setting/Range
On or off
Factory Default
On
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4.2.19 Temperature Sensor Control Mode (TS CLT Mode)
Purpose
The TS CONTROL MODE allows the selection of one of eight
possible temperature control modes for the controller. The different
modes allow redundant fail-safe temperature sensing.
Setting/Range
1. TS1-Fail ON
2.
Lowest Fail to Good
3.
Lowest Fail ON
4.
Average Fail to Good
5. Average Fail ON
6.
TS2 Fail to TS1
7.
TS2 Fail ON
8. TS1 Fail to TS2
Factory Default
TS1-Fail On
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4.2.20 External Input: Inhibit or Force on.
Purpose
Using an external input device to override sensor inputs: Force on or
force off
. Reference Figure 2.5 for the wiring connection schematic.
Setting/Range
Ext Input: Not used, Force on or Inhibit
Override: Remote or External input
Factory Default
Not used
Remote
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4.2.21 Firmware Version
Purpose
This menu displays the revision level of the firmware programmed
into the controller.
Setting/Range
N/A
Factory Default
N/A
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4.2.22 Passcode
Purpose
The four digit numeric PASSWORD stops unauthorized users from
modifying the controller’s configuration parameters using the
Operator Console.
Setting/Range
0000 to 9999
Factory Default
0000
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4.2.23 Communications Setup
Purpose
Defines the communications language used by the controller to
communicate with other devices. The
C910-485 only communicates
using
Modbus Protocol. The C910-485 automatically detects when it
is connected to the ACS
-30 network.
Setting/Range
See C910-485
Communication Parameters
Table
Factory Default
HTCBus
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C910-485 Communication Parameters
Parameter
Settings
Notes
Protocol
HTCBus (default)
Modbus
RTU
Modbus
ASCII
If you are communicating directly with the
controller using a different device, select the
MODBUS protocol.
For a detailed description of the controller’s
MODBUS mapping please refer to
C910-485 Heat
Trace Controller
.
Note: HTCBus is for factory use only.
Modbus Addr
1 - 247
Set the communications address as desired. Each
controller on the serial communication bus must
have its own unique address.
Modbus Baud
Rate
Auto, 9600, 4800,
2400
1200, 600, 300.
Default =Auto
Select the data rate to be compatible with other
devices that will be connected to the controller
for
communications
Purposes. It is recommended
that the
Setting be set to AUTO. The controller will
automatically select a BAUD RATE that is
compatible with the communications interface
installed.
Parity
NONE, EVEN, ODD
Defines the type of parity bit to be used with
MODBUS communications.
Select the desired type of p
arity. Note that PARITY
can only be selected when
using MODBUS
protocol.
Hardware
RS-485
Identifies the type of communications interface
installed in the
C910-485.
Driver
Auto, RS-485, RS232, Modem.
Defines the way in which the controller’s program
communicates with the communications interface.
Profile
Auto, 3-wire RS232,
RS485, 1200 BAUD
Modem, 300 BAUD
Modem
Defines the way in which the controller’s program
supports communications handshaking and
communication interface signals.
Tx Delay
0.00 to 2.50
seconds
Allows a programmable delay between the receipt
of a communications
message and the controller’s
reply. In some applications, it may be necessary to
delay the controller’s response to an inquiry for a
short period of time to allow external de
vices to
start up, stabilize
and/or synchronize.
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4.2.24 Auto-Cycle: Enabling
Purpose
The autocycle function applies power to the heating cable circuit for
approximate 10 seconds
at the selected interval. It is used to test the
integrity of the heating
cable circuit.
Note: Although the autocycle function helps monitor the
functionality of the heating cable circuits it does not eliminate the
need for preventive maintenance as detailed in the heating cable
operating manuals.
Setting/Range
Enable or disable
Factory Default
Disable
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4.2.25 Auto-Cycle: Interval
Purpose
Set the interval for running the autocycle procedure
Setting/Range
1 to 240 [minutes or hours, selected
in the Auto
-cycle units menu.]
Factory Default
8
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4.2.26 Auto-Cycle: Units
Purpose
Select the Autocycle interval time units.
Setting/Range
Minutes or hours
Factory Default
Hours
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4.2.27 Contactor Count
Purpose
Generates an alarm if the number of off-to-on transitions of a
contactor reaches or exceeds the C
ontactor Count Alarm Setting. This
serves as a
method to perform preventative maintenance on the
contactor before a failure is likely to occur
.
Setting/Range
0 to 999,999
Factory Default
200,000
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4.2.28 Monitor and Maintenance Menus
Purpose
The Monitor menu displays the measured and stored readings. You
can also reset counters from this menu.
Setting/Range
See C910-485 Monitoring
and Maintenance
Parameters t
able.
Factory Default
N/A
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RAYCHEM 910 Monitoring and Maintenance Parameters
Monitored variables
Description
CTL temp
Control Temp
TS1 temp
This temperature is the value that the controller is
reading from the RTD connected to its TS 1 input.
TS2 temp
This temperature is the value that the controller is
reading from the RTD connected to its TS 2 input, if the
sensor is being used.
Load current
Displays the current being drawn by the heating cable.
(A)
GFI current
Displays the ground-fault current being drawn by the
heating cable.
(mA)
Maintenance Tests
Trace testing
The TEST TRACING feature temporarily overrides the
temperature control, and power
s the heating cable
circuit for 30 seconds without having to modify the
CONTROL SETPOINT temperature or any other
configuration parameter.
Display test
The DISPLAY TEST feature provides an easy method of
illuminating eac
h display segment and all the LEDs of
the Operator Console to ensure that they are
functioning properly.
Recorded Values
Temperature values
This feature indicates the maximum and minimum
temperatures recorded by the
C910-485 since the last
time the values were reset
:
Max Control temp
Min Control temp
TS 1 Max Temp
TS 1 Min Temp
TS 2 Max Temp
TS 2 Min Temp
Contactor cycle count
This feature indicates the total number of off-to-on
transitions a contactor
has made since the last time the
CONTACTOR CYCLE COUNTER was reset.
(See
keystroke procedure for
resetting)
Time in use
Indicates the total hours in use of the controller since
its initial operation or since it was last reset.
Time since last reset
This feature indicates the total hours in use of the
controller since the last reset.
Peak ground-fault current
This feature indicates the highest instantaneous
gr
ound-fault current measured since the last time the
PEAK GROUND
-FAULT CURRENT was reset. This
current value is written to the controller’s non
-volatile
memory once every 24 hours or whenever any
maintenance data is reset by the user.
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4.2.29 Acknowledging and Resetting Alarms
Purpose
To acknowledge and reset any alarm conditions that may exist. Use
the
Up / Down Arrow keys to examine the next/previous active
alarms.
Setting/Range
See Alarm Filter Times
Factory Default
N/A Alarm Filter Times
Alarm Type
Filter Time
Lo TS 1 and 2
15 minutes
Hi TS 1 and 2
15 minutes
Lo load current
2 minutes
Hi ground-fault alarm
10 seconds
Hi ground-fault trip
< 1 second
OPEN / SHORTED TS 1 and 2
10 seconds
Contactor count
< 1 seconds
Switch failure
2 minutes
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4.2.30 Alarm Output Normal State
Purpose
Configures both the alarm output relays (dry contact and AC alarm)
for normally open or normally closed operation. The normal condition
is assumed to be when the HTC is powered and no alarms exist.
Setting/Range
Normally Open (N.O.) or
Normally Closed (N.C.)
Factory Default
Normally closed
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TROUBLESHOOTING Section 5
The C910-485 may be used as an effective troubleshooting tool to pinpoint problem
areas of heating cable circuits. Described below are a few of the more common problem
areas, their symptoms, and parameters to check to determine the actual faulty portion of
the heating cable circuit.
Symptom
Probable Cause
Corrective Action
RTD failure alarm
RTD is not a 3-wire 100
Ω Platinum
Install correct RTD
Damaged RTD sensor or
extension
cable
Install new RTD and/or cable
Incorrectly wired
Re-install RTD connections
Seemingly
incorrect
t
emperature
Incorrect RTD used
Install correct RTD
Damaged RTD sensor
or connection cable
Install new RTD and/or cable
C910-485 not
functioning correctly
Verify correct reading input Connect a
100
Ω resistor across the source or sense
terminal and common. Insert a jumper
between the source and sense terminals.
Apply power to the controller. The
indicated or displayed temperature should
be about 32°F (0°C).
Unstable or
bouncing
t
emperature
Bad, damaged or
incorrectly installed
RTD extension wire.
Wire used for extension of the RTD should
be three
-wire, twisted and shielded with
the shield grounded at the controller only.
Each of the three lead wires must be o
f
the same gauge.
Terminal connections
are not tight
Verify tightness of connections
RTD or extension cable
damaged
Install new RTD and/or cable
High temperature
TS 1/ TS 2
Alarm temperature
setting
too close to
maintain temperature
Increase setting
Flow of hot water
through pipe
Incorrect heating cable
wiring
Verify heating cable wiring
LOW temperature
TS 1/TS 2
Alarm temperature
setting
too close to
maintain temperature
Decrease setting
Heating cable not sized
properly for the
application
Refer to the appropriate heating cable
design guide for correct product selection
Damaged, wet, or
missing thermal
insulation
Replace or install correct thermal
insulation
Control TS failure
Failure of the RTD
designated as the
controlling sensor.
Check setting for TS FAIL MODE the
output switch may be latched off or on
until this failure is corrected
Incorrect or damaged
field wiring
Re-install RTD connections
Damaged temperature
sensors
Install correct RTD.
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Ground-fault
alarms
Incorrect installation,
wet system
components or
damaged cables.
Perform heating cable commissioning
tests outlined in the heat cable operation
manuals.
Incorrect neutral return
wiring
Check that the heating cable circuit
neutrals return to the controller and are
not connected directly to the distribution
panel.
Alarm setting too close
to normal leakage
current
Ground-fault level should be set at the
lowest level possible, but high enough to
allow normal operation of the cable.
WARNING: Fire Hazard. Ground-fault trip alarms must not be
ignored. To prevent the risk of fire, do not re
-energize heating
cables until the fault is identified and corrected.
Low current
Low or no source
voltage
Verify correct power distribution
Damaged or inoperative
heating cable
Repair or replace heating cable
Open connection—
wiring problem
Verify correct power distribution wiring
Contactor failed open
Replace or repair controller
Switch failure
Output switch has
failed “closed”
Replace or repair controller
Contactor count
Number of off-to-on
transitions of a
contactor has
exceeded the
CONTACTOR COUNT
ALARM
setting and the
contactor should be
replaced.
Inspect contactor and replace if
necessary.
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APPENDIX A: PROPORTIONAL AMBIENT SENSING CONTROL (PASC) Section 6
PASC takes advantage of the fact that the heat loss from a pipe is proportional to the
temperature difference between the pipe and the ambient air. This is true regardless of
heating cable, insulation type, or pipe size. Once the heat tracing and insulation on a
pipe has been designed to balance heat input with heat loss and maintain a particular
temperature, the main variable in controlling the pipe temperature becomes the ambient
air temperature.
The C910-485 has a control algorithm that uses the measured ambient temperature,
desired maintain temperature, minimum ambient temperature assumption used during
design, and size of the smallest pipe diameter to calculate how long the heating cable
should be on or off to maintain a near-constant pipe temperature. The power to the heat
tracing is proportioned based upon on the ambient temperature. If the ambient
temperature is at or below the “minimum design ambient plus 3°F” the heating cable will
be on 100%. If the measured ambient is at or above the “maintain temperature –3°F” the
heating cable will be on 0%. For any measured ambient between “minimum design
ambient” and “maintain temperature,” the heating cable will be on a percentage of the
time equal to (maintain temperature – measured ambient) / (maintain temperature –
minimum design temperature).
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North America
Tel +1.800.545.6258
Fax +1.800.527.5703
thermal.info@nvent.com
Europe, Middle East, Africa
Tel +32.16.213.511
Fax +32.16.213.604
thermal.info@nvent.com
Asia Pacific
Tel +86.21.2412.1688
Fax +86.21.5426.3167
cn.thermal.info@nvent.com
Latin America
Tel +1.713.868.4800
Fax +1.713.868.2333
thermal.info@nvent.com
©2018 nVent. All nVent marks and logos are owned or licensed by nVen t Services GmbH or its affiliates. All other trademarks are the property of their respective owners.
nVent reserves the right to change specifications without notice.
Raychem-IM-H58415-C910series-EN-1805
nVent.com
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