Table of Contents
Advertisement
TVOC MANUAL
5
Installation
5.3 Cable and gland requirements
Screened cables for both power and signal out are necessary to achieve EMC compliance. Cable
screens must be terminated at both ends for them to be effective in achieving electromagnetic
compatibility (EMC). The screens should be terminated to the TVOC enclosure using EMC compatible
cable glands. It is important for an EMC compatible gland to make electrical contact to the enclosure.
This is usually done using a serrated washer or EMC lock nut that bites through the paint making
electrical contact. EMC lock nuts have been provided. These locknuts are orientation specific the
points should be facing against the case in order to cut through the pain during tightening.
Two M20 ATEX cable glands and one ATEX blanking plug have been supplied as standard to ease
installation in most circumstances. These parts will not be appropriate for all applications so they
should be used at the discretion of the installation engineer. It is recommended that the
manufacturer's instructions are followed for the gland and blanking plug installation. The M20
blanking plug has been included to enable installations using a single entry cable (for example a
three wire system) to be implemented.
While ion science can not recommend the cable gland suitable for every application the following
information may be useful to the installation engineer for the selection of the appropriate cable
gland.
For ATEX Ex i (intrinsically safe) operation using safety barriers, the only requirements on
the cable glands are that they are better than IP20 rated. This may seem extraordinary
however where the power is safely limited to the TVOC it is intrinsically safe so does not rely
on the prevention of dirt or moisture into the enclosure.
For ATEX Ex n the Cable glands must be ATEX rated (Ex e, Ex n or Ex d) and at least IP54.
5.4 Power requirements
5.4.1 Non ATEX applications:
Input power
4-20mA power
4 Wire System
Diagram 5.4.1
3 Wire System
5 - 28Vdc. 80mA max.
8-35Vdc. 22mA
Page 12 of 28
Ion Science Ltd
Advertisement
Table of Contents
