EATON MTL K522 Gas Analysers and Systems Instructions
- June 12, 2024
- EATON
Table of Contents
CROUSE-HINDS SERIES
Technical note
MTL gas analysers & systems
MTL K522
grounding techniques
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.
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.
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
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.
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.
Eaton Electric Limited,
Great Marlings, Butterfield, Luton
Beds, LU2 8DL, UK.
Tel: + 44 (0)1582 723633
Fax: + 44 (0)1582 422283
E-mail: mtlgas@eaton.com
www.mtl-inst.com
EUROPE (EMEA):
+44 (0)1582 723633
mtlenquiry@eaton.com
THE AMERICAS:
+1 800 835 7075
mtl-us-info@eaton.com
ASIA-PACIFIC:
+65 6 645 9888
sales.mtlsing@eaton.com
© 2016 Eaton
All Rights Reserved
Publication No. TN010 520-1009 Rev 3 191016
October 2016