SKF CMPT CTU User manual

SKF Copperhead Transmitter Unit (CMPT CTU)
for Machinery Fault Detection
Copyright © 2011 by SKF Reliability Systems
All rights reserved.
Aurorum 30, 977 75 Luleå
Sweden
Telephone: [phone], Fax: [phone]
Part No. 32163100
Revision D
Instruction Manual

SKF Reliability Systems
SKF Condition Monitoring Center
Aurorum 30
977 75 Luleå
Sweden
Telephone [phone]
FAX [phone]
For technical support, contact:
[email protected]
or
[email protected] for customers in North and South
America.
Visit us at our web site
www.skf.com/cm
® SKF is a registered trademark of the SKF Group

SKF Copperhead Transmitter Unit CMPT CTU TOC-3
Instruction Manual
Table of Contents
Description 1 - 4
Features 2 - 5
Specifications 3 - 7
Dimensions/Front panel/Terminals 4 - 9
....................................................................................................4 - 9
Front Panel Rotary Switches
....................................................................................................4 - 11
Connector Assignment
Caution 5 - 12
CMPT CTU Output Signal Scales 6 - 13
....................................................................................................6 - 13
Vibration
....................................................................................................6 - 16
Temperature
Basic Instructions and Wiring Connections 7 - 17
....................................................................................................7 - 17
General Instructions
....................................................................................................7 - 18
Normal Wiring as Vibration and Temperature (optional) Transmitter
....................................................................................................7 - 20
Normal Wiring as Vibration and Temperature (optional) Transmitter with
CMPT DCL Modules for Stand Alone Monitoring
....................................................................................................7 - 21
Parallel Wiring with Secondary CTU
CMPT CTU Output 8 - 22
Interface with Dataloggers and Vibration Systems 9 - 24
CTU CAN-bus 10 - 25
....................................................................................................10 - 25
CTU CAN-bus Connection
....................................................................................................10 - 27
CTU CAN Protocol
....................................................................................................10 - 28
Services
....................................................................................................10 - 30
Unit Address
....................................................................................................10 - 32
Overall Measurement Values

Description
SKF Copperhead Transmitter Unit CMPT CTU1-4
Instruction Manual
Description
1
Figure 1-1: CMPT CTU (Copperhead Transmitter Unit)
This instruction manual provides detailed wiring connection and configuration
information for the CMPT CTU (Copperhead Transmitter Unit) vibration and
temperature transmitter. The CMPT CTU is configured by SKF when it is part of an
assembled CMPT enclosure. The CMPT CTU must otherwise be properly installed and
configured by the user. This instruction manual provides the user with information on
how to properly install and configure the CTU and change the default configuration
settings.
Please read this instruction manual and the cautionary notes thoroughly.
The SKF CTU is a digital vibration and temperature transmitter. It can be used as a part
of a machinery fault detection system. The CTU performs three types of vibration signal
process analysis – SKF Acceleration Enveloping (gE), Acceleration (g), or Velocity (mm/s
or inch/s). The type of vibration analysis is user configurable. The CTU has analog
output signals proportional to processed vibration analysis and temperature for
connection to automation systems and SKF CMPT DCL monitors. The CTU is user
configurable to process vibration signals from the SKF CMPT family of sensors or other
industrial accelerometers.
Acceleration Enveloping vibration analysis is used to identify repetitive impact type
vibrations generated by machinery faults due to loose components, gear faults, lack of
lubrication and rolling bearing faults.
Acceleration vibration analysis is used to monitor overall machinery and structural
vibration, including machinery having journal bearings. It can also be used to measure
the overall operation of vibrating screens and other vibrating equipment.
Velocity vibration analysis is used to identify overall machinery vibration levels such as
looseness and unbalance, including machinery support by journal bearings.
The CMPT CTU has unique features to monitor both high speed and low speed
machinery (n <40 r/min).

SKF Copperhead Transmitter Unit CMPT CTU 2-5
Features
Instruction Manual
Features
2
·Suitable with accelerometer sensors (10 mV/g to 230 mV/g).
·Temperature converter for accelerometers with integral temperature sensors.
·Three user selectable vibration process analyses:
- SKF Acceleration Enveloping (ENV3), gE
- Acceleration (RMS and Peak Hold), g
- Velocity ISO, mm/s (inch/s)
·User configurable features on the front panel:
- Vibration analyzer
- Output Range
- Optional sensor input or buffered vibration output input
- Optional signal decay for Acceleration Enveloping Peak hold
- Optional output signal averaging.
·Analog output signals - Processed vibration and temperature for interface with
PLC/DCS and CMPT DCL alarm/display monitors.
·35 mm DIN rail mounted with rugged steel retainer clip.
·Front panel mounted BNC connector for buffered vibration and temperature
measurements.
·Front panel sensor OK/Overload lamp for detection of sensor and CTU faults.
·CAN-bus interface for connectivity of multiple numbers of CTU and remote
monitoring via computer.
·Internal isolated DC/DC converter for grounding loop and reverse polarity
protection.
·Auxiliary 24 V DC voltage output for optional powering of other sensor types
(tachometer).
The software to process the vibration and temperature signals is embedded into the
digital signal processing (DSP) card in the CTU. Calibration of the CTU is a part of the
embedded software.
The CTU unit has two front panel rotary switches to set the configuration. There is no
need to open the CTU enclosure to adjust pins or jumpers. The BNC connector is front
panel switchable (BNC switch) to measure either the accelerometer sensor buffered
(not processed) vibration output or the sensor temperature output. The buffered
vibration output can be monitored with an SKF Microlog or equivalent device.
The CTU has a user configurable option to average the analog output signals so that
rapid changes in vibration input do not cause annoying fluctuations in PLC/DCS or
digital displays.
The CTU has a user configurable option of 1 second or 10 second signal decay time for
Acceleration Enveloping Peak hold. The 10 second signal decay time is recommended
for low speed (n <40 r/min) applications where the frequency of the mechanical impact
vibration is low. Normal operation of the CTU is with the 1 second signal decay time.
The CTU can be user configured to accept a constant current signal from another CTU
operating with an accelerometer sensor. This enables two CTUs having different
configurations such as one Acceleration Enveloping and one Velocity to monitor the
same accelerometer sensor signal.

Features
SKF Copperhead Transmitter Unit CMPT CTU2-6
Instruction Manual
The CTU has a front panel mounted SENSOR OK lamp to indicate that the sensor is
correctly connected to the CTU and that the sensor (accelerometer and temperature)
and the CTU are operating correctly.
- Green indicates that the system is OK (Correct).
- Red indicates that the system has a fault with the sensor or CTU, or that the
vibration level or temperature exceeds the set RANGE (overload).
The CTU can be located up to 100 m (330 feet) from the sensor with suitable shielded
cabling. The CMPT DCL display/alarm module can be used along with the CMPT CTU
module to have a stand-alone monitoring of processed vibration. A second DCL module
can be used to optionally monitor temperature from a CTU connected to a CMPT 2310T
or CMPT 2323T sensor. The CMPT DCL is a single channel display/alarm module. It
displays the live value from CTU on the front panel which is programmable. IT also has
relay contacts for independent monitoring of the processed signals from the CTU. See
the CMPT DCL data sheet.
Each CTU has a CAN-bus interface for remote communication with an industrial PC
using an SKF protocol software. This enables remote configuration and monitoring of
the CTU. The CAN-bus allows multiple numbers of CTU modules to be joined by a
common CAN-bus connecting cable. This greatly reduces the wiring connections needed
compared to the analog output signal cable requirements.
The CTU has an auxiliary 24 V DC power output for optional use to energize alternative
sensors (20 mA maximum).
The CTU has an internal isolated DC/DC converter to avoid grounding loop problems.
This isolates the 24 V power supply and the CAN-bus from the sensor input circuitry
and the analog sensor output circuitry. The power input is protected from reverse
polarity connections.

SKF Copperhead Transmitter Unit CMPT CTU 3-7
Specifications
Instruction Manual
Specifications
3
Input signals
Industrial accelerometer (2 wire, constant current source with voltage output)
Accelerometer sensitivity: 10 to 230 mV/g
Bias voltage: 12 V DC +/- 1 V
Supply current: 4 to 8 mA
Buffered acceleration signal
output from another CTU Buffered signal input mode
Supply voltage: 5 to 19 V
Temperature: 0 to 1,2 V DC @ 0,01 mV/°C
Environmental
Operating temperature: 0 to 70 °C (32 °F to 160 °F)
Storage temperature: -40 °C to 85 °C (-40 °F to 185 °F)
Humidity: 95 % maximum
IP rating: IP20
Vibration: IEC68-2-6
Shock: IEC68-2-27
Bump: IEC68-2-29
Mechanical
Weight: 0,225 kg (0,102 lbs)
Enclosure: Thermoplastic ABS
Color: Gray
Connectors: Two 8-pole pluggable screw clamp type
Wiring: 0,2 to 2,5 mm (24 to 12 AWG)
Mounting: 35 mm DIN-rail type EN50022 with steel retaining
clip
Dimensions (H x W x D): 75 x 45 x 118 mm
(2,95 x 1,77 x 4,65 inches)
Electrical
Power: 24 V DC (22 to 28 V DC)
250 mA current, maximum
CTU is reverse power protected
Power consumption: 6 W
Vibration process analysis
Acceleration Enveloping, gE
ENV3: 500 Hz – 10 kHz
Acceleration, g
Accel RMS: 3 Hz – 10 kHz
Accel Peak Hold: 3 Hz – 10 kHz
Velocity, mm/s (inch/s)
ISO: 10 Hz – 1 kHz
2 Hz – 1 kHz

Specifications
SKF Copperhead Transmitter Unit CMPT CTU3-8
Instruction Manual
Processed analog output signals
Vibration: 4 to 20 mA; 0 to 10 V DC
Proportional to the input sensitivity of the
accelerometer and the user defined signal
processing method (Acceleration Enveloping,
Acceleration or Velocity) and RANGE.
See Section 3.
Temperature: 4 to 20 mA; 0 to 10 V DC
Proportional to 0 °C to 120 °C
Analog signal less than 4 mA or greater than 20 mA indicates a system fault.
Auxiliary power:+24 V DC / 20 mA maximum
Approvals: CE
Emission 50081-2
Immunity 50082-2

SKF Copperhead Transmitter Unit CMPT CTU 4-9
Dimensions/Front panel/Terminals
Instruction Manual
Dimensions/Front panel/Terminals
4
Front Panel Rotary Switches
Figure 4-2: Dimensions and front panel
FUNCTION switch legend
0 Velocity (ISO), 10 Hz – 1 kHz
1 Velocity, 2 Hz – 1 kHz
4 Acceleration Peak Hold, 1 second decay
5 Acceleration Peak Hold, 10 seconds decay
6 Acceleration RMS, 1 second decay
7 Acceleration RMS, 10 seconds decay
C Acceleration Enveloping 3 (ENV3), 1 second decay
D Acceleration Enveloping 3 (ENV3), 10 second decay
RANGE switch legend
0 Range 0, Accelerometer sensor input ON, Output averaging OFF
1 Range 1, Accelerometer sensor input ON, Output averaging OFF
2 Range 2, Accelerometer sensor input ON, Output averaging OFF
3 Range 3, Accelerometer sensor input ON, Output averaging OFF
4 Range 0, Accelerometer sensor input ON, Output averaging ON
5 Range 1, Accelerometer sensor input ON, Output averaging ON
6 Range 2, Accelerometer sensor input ON, Output averaging ON
7 Range 3, Accelerometer sensor input ON, Output averaging ON
8 Range 0, Buffered signal input ON, Output averaging OFF
9 Range 1, Buffered signal input ON, Output averaging OFF
A Range 2, Buffered signal input ON, Output averaging OFF
B Range 3, Buffered signal input ON, Output averaging OFF
C Range 0, Buffered signal input ON, Output averaging ON
D Range 1, Buffered signal input ON, Output averaging ON
E Range 2, Buffered signal input ON, Output averaging ON
F Range 3, Buffered signal input ON, Output averaging ON

Dimensions/Front panel/Terminals
Front Panel Rotary Switches
SKF Copperhead Transmitter Unit CMPT CTU4-10
Instruction Manual
SENSOR OK lamp
Green Accelerometer and temperature sensor and CTU are
operating correctly
Green (flashing) CTU is settling output because of change in rotary switch
setting
Red Fault with sensors or vibration exceeds set RANGE *
Red (flashing) Vibration or temperature input signal exceeds full Scale
Red/Green (flashing) Unit failure (return to SKF for repair)
* The SENSOR OK lamp will be red if the temperature sensor is not connected. A 100 Wor a 120 Wresistor
is required between CTU terminals 2 and 3 to avoid the red SENSOR OK lamp.

SKF Copperhead Transmitter Unit CMPT CTU 4-11
Dimensions/Front panel/Terminals
Connector Assignment
Instruction Manual
Connector Assignment
Figure 4-3: CMPT CTU connector assignment
Pin Number Connection Description
1 ACC SIGNAL/PWR Accelerometer signal
2 ACC SIGNAL GND Accelerometer ground
3 TEMP SIGNAL High Temperature signal (optional)
4 AUX SENSOR PWR Powering of auxiliary sensor
(optional)
5 CAN-bus HIGH See CTU CAN-bus
6 CAN-bus LOW See CTU CAN-bus
7 POWER +24 V DC Power supply for CTU
8 POWER SUPPLY GND Power supply ground
9 BUFFERED VIB OUT Buffered (not processed) vibration
signal
10 BUFFERED VIB GND Buffered vibration signal ground
11 4–20 mA TEMP OUT Analog signal for temperature
12 TEMP COMMON OUT Common (ground) for temperature
13 0–10 V TEMP OUT Analog signal for temperature
14 4–20 mA VIB OUT Analog signal for processed
vibration
15 VIB COMMON OUT Analog signal common (ground) for
vibration
16 O–10 V VIB OUT Analog signal for processed
vibration

Caution
SKF Copperhead Transmitter Unit CMPT CTU5-12
Instruction Manual
Caution
5
Read and understand these instructions thoroughly before working with the CMPT CTU.
The CMPT CTU should be installed by persons qualified to work with electrical
instrumentation.
Caution - Damage or injury can result
•The CMPT CTU is powered by 24 V DE. Do not apply higher voltage.
•Higher voltage (110–240 V AC) power may exist in the same proximity as the
CMPT CTU. Use caution to avoid contact with any voltage source.
•Make sure that the CMPT CTU is installed in an environment within its
specifications (see section "Specifications")
Lightning strikes, power surges and other electrical anomalies can damage this device.
For the protection of your equipment, SKF recommends the power connections be
made through a surge protector.

SKF Copperhead Transmitter Unit CMPT CTU 6-13
CMPT CTU Output Signal Scales
Instruction Manual
CMPT CTU Output Signal Scales
6
Vibration
The accelerometer sensor and CMPT CTU unit provide processed vibration and
temperature (optional) analog signals for use with a CTU module and for PLC/DCS
systems for continuous monitoring. The scale of the CTU vibration analog output signal
in engineering units (gE, g, mm/s or inch/s (IPS)) depends on the setting of the rotary
FUNCTION and RANGE switches and the sensitivity of the selected accelerometer
sensor. See Table 6-1 and Table 6-2 below for the full scale (RANGE) values of the CTU
depending on the type of vibration analysis mode, sensor sensitivity, and selected CTU
RANGE.
Examples for the setting of the FUNCTION and RANGE:
Example 1
Sensor 100 mV/g
CTU settings
FUNCTION switch C (Acceleration Enveloping ENV 3)
RANGE switch 2 (full Scale = 30 gE)
Output signal scale
Vibration 0–30 gE3 (4 to 20 mA and 0 to 10 V DC)
Temperature 0–120 °C (4 to 20 mA and 0 to 10 V DC)
Example 2
Sensor 100 mV/g
CTU settings
FUNCTION switch 0 (Velocity ISO)
RANGE switch 2 (full Scale = 15 mm/s)
Output signal scale
Vibration 0–15 mm/s (4 to 20 mA and 0 to 10 V DC)
Temperature 0–120 °C (4 to 20 mA and 0 to 10 V DC)
Example 3
Sensor 230 mV/g
CTU settings
FUNCTION switch C (Acceleration Enveloping)
RANGE switch 0 (full Scale = 1,3 gE3)
Output signal scale
Vibration 0–1,3 gE3 (4 to 20 mA and 0 to 10 V DC)
Temperature 0–120 °C (4 to 20 mA and 0 to 10 V DC)

CMPT CTU Output Signal Scales
Vibration
SKF Copperhead Transmitter Unit CMPT CTU6-14
Instruction Manual
The following Table 6-1 lists the vibration gain (unit/V) and scale values of Velocity
mode, ISO and Non-standard ISO.
Sensor (RMS)
RANGE 0
RANGE 1
RANGE 2
RANGE 3
230 mV/g
Metric (RMS)
Gain
Scale
0,065 mm/s/V
0 to 0,65 mm/s
0,22 mm/s/V
0 to 2,17 mm/s
0,65 mm/s/V
0 to 6,5 mm/s
2,2 mm/s/V
0 to 21,74
mm/s
100 mV/g
Metric (RMS)
Gain
Scale
0,15 mm/s/V
0 to 1,50 mm/s
0,50 mm/s/V
0 to 5,00 mm/s
1,5 mm/s/V
0 to 15,00
mm/s
5,0 mm/s/V
0 to 50 mm/s
30 mV/g
Metric (RMS)
Gain
Scale
0,5 mm/s/V
0 to 5 mm/s
1,67mm/s/V
0 to 16,7 mm/s
5,0 mm/s/V
0 to 50 mm/s
16,7 mm/s/V
0 to 167 mm/s
10 mV/g
Metric (RMS)
Gain
Scale
1,5 mm/s/V
0 to 15 mm/s
5,0 mm/s/V
0 to 50 mm/s
15 mm/s/V
0 to 150 mm/s
50 mm/s/V
0 to 500 mm/s
Sensor (Peak)
RANGE 0
RANGE 1
RANGE 2
RANGE 3
230 mV/g
English (IPS
Ps. PK)
Gain
Scale
0,0036 IPS/V
0 to 0,036 IPS
0,012 IPS/V
0 to 0,12 IPS
0,036 IPS/V
0 to 0,36 IPS
0,121 IPS/V
0 to 1,21 IPS
100 mV/g
English (IPS
Ps. PK)
Gain
Scale
0,008 IPS/V
0 to 0,08 IPS
0,027 IPS/V
0 to 0,27 IPS
0,084 IPS/V
0 to 0,84 IPS
0,28 IPS
0 to 2,78 IPS
30 mV/g
English (IPS
Ps. PK)
Gain
Scale
0,028 IPS/V
0 to 0,28 IPS
0,093 IPS/V
0 to 0,93 IPS
0,28 IPS/V
0 to 2,8 IPS
0,93 IPS/V
0 to 9,3 IPS
10 mV/g
English (IPS
Ps. PK)
Gain
Scale
0,084 IPS/V
0 to 0,84 IPS
0,28 IPS/V
0 to 2,8 IPS
0,84 IPS/V
0 to 8,4 IPS
2,8 IPS/V
0 to 28 IPS
Table 6-1: Velocity mode, ISO and Non-standard ISO

SKF Copperhead Transmitter Unit CMPT CTU 6-15
CMPT CTU Output Signal Scales
Vibration
Instruction Manual
The following Table 6-2 lists the vibration gain (unit/V) and scale values of Acceleration
(g) and Acceleration Enveloping (gE).
Sensor
RANGE 0
RANGE 1
RANGE 2
RANGE 3
230 mV/g
Gain
Scale
0,13 gE/V
0 to 1,3 gE
0,44 gE/V
0 to 4,4 gE
1,3 gE/V
0 to 13 gE
4,4 gE/V
0 to 43,5 gE
100 mV/g
Gain
Scale
0,3 gE/V
0 to 3 gE
1,0 gE/V
0 to 10 gE
3,0 gE/V
0 to 30 gE
10,0 gE/V
0 to 100 gE
30 mV/g
Gain
Scale
1,0gE/V
0 to 10 gE
3,3 gE/V
0 to 33,3 gE
10,0 gE/V
0 to 100 gE
33,3 gE/V
0 to 333 gE
10 mV/g
Gain
Scale
3,0 gE/V
0 to 30 gE
10,0 gE/V
0 to 100 gE
30,0 gE/V
0 to 300 gE
100,0 gE/V
0 to 1 000 gE
Table 6-2: Acceleration (g) and Acceleration Enveloping (gE)
Values of vibration (V) in the machinery being monitored can be calculated from the
measured analog output current signal of the CTU (terminals 14 and 15) using the
following equation:
S (C - 4)
16
L =
Where as;
L = vibration level in machine (gE, g, mm/s, IPS)
S = full RANGE scale (gE, g, mm/s, IPS) of the CTU
C = measured current output from CTU (mA) between 4 and 20 mA
The vibration level (L) in the machinery being monitored can be calculated from the
measured analog DC voltage signal of the CTU (terminals 15 and 16) using the
following equation:
V x S
10
L =
Where as;
L = vibration level in machine (gE, g, mm/s, IPS)
V = measured voltage output from CTU (V) between 0 and 10 V DC
S = full RANGE scale (gE, g, mm/s, IPS) of the CTU

CMPT CTU Output Signal Scales
Temperature
SKF Copperhead Transmitter Unit CMPT CTU6-16
Instruction Manual
Temperature
The CTU temperature analog output signals is constant at 0 °C to 120 °C (32 °F to 248
°F) equal to 4 to 20 mA and 0 to 10 V DC.
Values of temperature (T) in the machinery being monitored can be calculated from the
measured analog current (mA) output signal of the CTU (terminals 11 and 12) using the
following equation:
120 (C - 4)
16
T =
Where as;
T = temperature level in machine (°C)
C = measured current output from CTU (mA) between 4 and 20 mA
Or
216 (C - 4)
16
+ 32
T =
Where as;
T = temperature level in machine (°F)
V = measured current output from CTU (mA) between 4 and 20 mA
The temperature (T) in the machinery being monitored can be calculated from the
measured analog DC voltage signal of the CTU (terminals 12 and 13) using the
following equation:
T = 12 x V
Where as;
T = temperature level in machine (°C)
V = measured voltage output from CTU (V) between 0 and 10 V DC
Or
T = (21.6 x V) + 32
Where as;
T = temperature level in machine (°F)
V = measured voltage output from CTU (V) between 0 and 10 V DC

SKF Copperhead Transmitter Unit CMPT CTU 7-17
Basic Instructions and Wiring Connections
Instruction Manual
Basic Instructions and Wiring Connections
7
General Instructions
The accelerometer sensor and CMPT CTU should be located within 100 m (300 feet) of
each other. A suitable twisted and shielded pair of wires (22 AWG with 100 pF/m)
should be used to connect the CMPT 2310 and CMPT 2323 accelerometer sensors to
the CTU. Three wires are needed for the CMPT 2310T and CMPT 2323T sensors.
Set the CTU rotary FUNCTION and RANGE switches to configure the transmitter for the
desired vibration analysis mode and the desired output signal scale. The FUNCTION
switch setting defines the type of vibration analysis (Acceleration Enveloping,
Acceleration, or Velocity) and the RANGE setting defines the output signal scale. The
RANGE setting also defines the type of input source (accelerometer sensor or a buffered
signal input from another CTU).
The CTU can be mounted horizontally or vertically on a DIN rail. It is advisable to use
DIN spacers between the CTU modules. The CTU must be installed in an area with
sufficient cooling.
The following Table 7-3 shows general recommendations on the selection of the
vibration accelerometer and the RANGE and signal decay settings for the CTU
depending on the speed of the application.
Application conditions
Normal speed
Low speed (n < 40 r/min)
Sensor
CMPT 2310 or
CMPT 2310T
CMPT 2323 or
CMPT 2323T
CMPT CTU settings
Output RANGE
1, 2 or 3
0 or 1
Vibration signal decay
1 second
10 seconds
Table 7-3: CTU application conditions
The analog output signals can be averaged using the appropriate RANGE switch setting.
This will reduce the variation of the signal display for visual observation with a CMPT
DCL display/alarm module or in the PLC/DCS system.
After the CTU FUNCTION and RANGE switches are set, apply the self-adhesive stickers
provided with the CTU to the front panel of the CTU corresponding to the selected
FUNCTION and RANGE settings.

Basic Instructions and Wiring Connections
Normal Wiring as Vibration and Temperature (optional) Transmitter
SKF Copperhead Transmitter Unit CMPT CTU7-18
Instruction Manual
Normal Wiring as Vibration and Temperature (optional) Transmitter
This applies to SKF CMPT sensors 2310, 2310T, 2323 and 2323T.
The sensor ground wire is connected to the inner shield of the sensor cable. This wire should be connected to
ground (earth) inside the CMPT CTU enclosure. The sensors have a stainless steel over braid. The braid is
for mechanical protection of the cable. The braid also acts as an outer shield. It is advised to isolate (shield)
the sensor ground wire from the braid and local ground. The cable braid and the sensor ground wire should
not contact each other or else a “ground loop” may occur causing signal interference.
Figure 7-4: Basic CMPT CTU with wiring
The CMPT accelerometer sensor is connected to the CMPT CTU according to the wiring
diagram in Figure 7-4.
The CTU can directly interface with a plant automation system via a Programmable
Logic Controller (PLC) / Distributed Control System (DCS) using both the processed
vibration and temperature analog output signals. The accelerometer and CTU can be
located up to 1,6 km (1 mile) away from the PLC/DCS when using the 4-20 mA current
signal outputs and recommended wire size (2,5 mm (22 AWG) at 100 pF/m).
The processed vibration signals of the CTU can be “averaged” to dampen the change in
processed vibration output signal. This feature is useful if the vibration level in the
machine is dynamic making the setting of alarm(s) in the PLC/DCS difficult or the
observation of the PLC / DCL digital display uncomfortable for the operator. Use RANGE
settings 4 to 7 or C to F to enable the “Output averaging ON” configuration.
The SENSOR OK lamp will be red if the temperature sensor is not connected. A 100 W
or a 120 Wresistor is required between CTU terminals 2 and 3 to avoid the red
SENSOR OK lamp.

SKF Copperhead Transmitter Unit CMPT CTU 7-19
Basic Instructions and Wiring Connections
Normal Wiring as Vibration and Temperature (optional) Transmitter
Instruction Manual
Basic connections (Basic CMPT CTU with wiring):
Accelerometer CTU terminal
ACC Signal / Power (White) 1
ACC / TEMP signal Ground (Black) 2
TEMP signal High (Red) 3
Power +24 V DC 7
Power Ground 8
Analog output (current)
Vibration
4 to 20 mA 14
Vibration common 15
Temperature
4 to 20 mA 11
TEMP common 12
Alternative analog output (voltage)
Vibration
0 to 10 V DC 16
Vibration common 15
Temperature
0 to 10 V DC 13
TEMP common 12

Basic Instructions and Wiring Connections
Normal Wiring as Vibration and Temperature (optional) Transmitter with CMPT DCL Modules for Stand Alone Monitoring
SKF Copperhead Transmitter Unit CMPT CTU7-20
Instruction Manual
Normal Wiring as Vibration and Temperature (optional) Transmitter with CMPT
DCL Modules for Stand Alone Monitoring
An accelerometer sensor and CMPT CTU can be connected to a CMPT DCL module for
stand alone vibration monitoring. A second DCL module may be used for optional
temperature monitoring. The DCL module provides a digital display of the processed
vibration (or optional temperature) signal and has a single alarm and relay function for
local annunciation of a change in vibration or temperature. See the wiring diagram in
Figure 7-5 and refer to the CMPT DCL Instruction Manual for wiring and setting details.
This applies to SKF CMPT sensors 2310, 2310T, 2323 and 2323T.
The sensor ground wire is connected to the inner shield of the sensor cable. This wire should be connected to
ground (earth) inside the CMPT CTU enclosure. The sensors have a stainless steel over braid. The braids for
mechanical protection of the cable. The braid also acts as an outer shield. It is advised to isolate (shield) the
sensor ground wire from the braid and local ground (earth). The cable braid and the sensor ground wire
should not contact each other or else a “ground loop” may occur causing signal interference.
Figure 7-5: CMPT sensor and CTU connected with two CMPT DCL display/alarm
modules for stand alone monitoring with a temperature sensor
The SENSOR OK lamp will be red if the temperature sensor is not connected. A 100 W
or a 120 Wresistor is required between CTU terminals 2 and 3 to avoid the red
SENSOR OK lamp.