MTL K522 Gas Analysers and Systems
Product Information
The MTL K522 is a gas analyzer and system designed for use in
various applications. It features an RS232 interface for
communication with remote sensors and communication equipment. The
instrument has multiple terminals for signal grounding, output
supply, and power supply.
Signal Grounding
The signal grounding terminals are as follows:
- Terminal 5: 0V
- Terminal 6: Common (Green)
- Terminal 7: Reference (Red)
Output Supply
The output supply terminals are as follows:
- Terminal 13: Supply (+) 24Vdc
- Terminal 14: Supply (-) 0V
Sensor RS232
The sensor RS232 terminals are as follows:
- Terminal 1: RX (In)
- Terminal 2: TX (Out)
- Terminal 3: CTS (In)
- Terminal 4: RTS (Out)
Internal Connections
The internal connections of the MTL K522 are shown in Figure 1.
Please refer to this diagram for understanding the internal
wiring.
Chassis Grounding & Earth Grounding
The instrument provides two cable screening methods for chassis
grounding and earth grounding. These methods are shown in Figures 2
and 3. It is important to note that the sensor is isolated from its
metal enclosure, ensuring no external connection to chassis ground
or earth ground.
Product Usage Instructions
- Connect the RS232 port of the MTL K522 instrument to a PC using
the appropriate cable. - If connecting to a PC, ensure that the GND terminal is
connected to the PC case, which should be connected to mains earth
ground. - For proper power supply, use a Class II or double insulated DC
power supply that is not earthed. - Refer to the provided diagrams (Figures 2 and 3) for cable
screening methods if chassis grounding and earth grounding are
required. - Follow the appropriate cable screening method to ensure proper
grounding.
If you require further technical support or have any questions
regarding the MTL K522 gas analyzer, please contact Eaton Electric
Limited using the provided contact information.
Technical note
MTL gas analysers & systems
MTL K522
grounding techniques
October 2016 TN010 520-1009 Rev 3
Introduction
This technical note is to aid the wiring on site of MTL K522 Instruments, remote sensors and communication equipment using the RS232 interface.
Signal Grounding
The RS232 0V, Sensor Common and Supply 0V and are all connected together internally See Figure 1. It is important that these terminals are not connected to external circuits at differing potentials. This includes connections to mains earths in different locations. The Output 4/20mA is an isolated output.
Output Supply
Sensor RS232
1 RX (In) 2 TX (Out) 3 CTS (In)
4 RTS (Out) 5 0V 6 Common (Green) 7 Reference (Red)
8 Measure (Blue) 9 NC 10 NC 11 NC 12 NC 13 Supply (+) 24Vdc 14 Supply (-) 0V 15 4/20 mA (+) ve 16 4/20 mA (-) ve
PC
Shield
Sensor RS232
1 RX (In) 2 TX (Out) 3 CTS (In) 4 RTS (Out) 5 0V 6 Common (Green) 7 Reference (Red) 8 Measure (Blue) 9 NC
10 NC 11 NC 12 NC 13 Supply (+)24Vdc 14 Supply (-) 0V 15 4/20 mA (+) ve 16 4/20 mA (-) ve
(internaly connected)
Function: RS232 Communications Sensor
Power supply Output
Output Supply
Figure 1 – Internal connections
When the RS232 port is connected to a PC, the GND terminal will be connected to the PC case, and hence to mains earth ground. In this case, the DC power supply for the instrument should be a Class II or double insulated type (ie not earthed).
Chassis Grounding & Earth Grounding
Depending on the installation these might be connected together or they might not. However for the discussion below, we have assumed they are connected together and have ignored the earth ground symbol. If signal cables lengths are greater than 0.5m or close to sources of electrical noise, instrument performance may be improved by using screened cables. In this case the screens should be terminated at one (the same) end to a single bonding point (ie RS232 D type shield if this linked to earth). See Figure 2.
Output Supply
Sensor RS232
Figure 2 – Cable screening method
If the serial interface is not connected then it is advised to connect the () 0v side of the DC supply to the earth bonding point. See Figure 3
1 RX (In) 2 TX (Out) 3 CTS (In) 4 RTS (Out) 5 0V 6 Common (Green) 7 Reference (Red) 8 Measure (Blue) 9 NC 10 NC 11 NC 12 NC 13 Supply (+) 24Vdc 14 Supply (-) 0V 15 4/20 mA (+) ve 16 4/20 mA (-) ve
Figure 3 – Alternative cable screening method
In either of the cases above, the sensor is isolated from its metal enclosure and will therefore not cause any external connection to chassis ground or earth ground.
Eaton Electric Limited, Great Marlings, Butterfield, Luton Beds, LU2 8DL, UK. Tel: + 44 (0)1582 723633 Fax: + 44 (0)1582 422283 E-mail: [email protected] www.mtl-inst.com
© 2016 Eaton All Rights Reserved Publication No. TN010 520-1009 Rev 3 191016 October 2016
EUROPE (EMEA): +44 (0)1582 723633 [email protected]
THE AMERICAS: +1 800 835 7075 [email protected]
ASIA-PACIFIC: +65 6 645 9888 [email protected]
The given data is only intended as a product description and should not be regarded as a legal warranty of properties or guarantee. In the interest of further technical developments, we reserve the right to make design changes.
