MIC440 Explosion Protected CCTV Camera System| Installation and Operation Manual
EN | 13
Bosch Security Systems
Issue 6
Earthing of the MIC440 Camera
1.
The camera module & housing are electrically isolated so the housing
should be safety earthed regardless. The safety earth should be a bonding
connection to the cameras outside case for example one of the securing
bolts.
2.
The camera should be earthed at one point only to prevent earth loops &
thus hum bars showing on the control room monitor.
3.
If the system is copper throughout & the camera pictures are fed back to
the control room coaxial copper cable, then the camera should be earthed
at the video termination point in the control room & nowhere else. In this
case the PCB “Earth Link” should be broken.
4.
If the video is transmitted back to the control room via some non electrical
connecting medium, e.g. fibre optic, radio or microwave link, then the
camera should be earthed at the transmitter point in the psu. The PSU
“Earth Link” may be used for this purpose.
5.
If dual earthing is unavoidable then a video isolation transformer should be
fitted between the two earths.
Lightning Protection
If the camera is fitted in a highly exposed place then consideration should be given
to lightning protection. A good earth bonding connection to the case itself will
provide protection against damage from secondary strikes.
Where there is a risk of a primary strike hitting the camera housing directly, it is
recommended that a separate lightning conductor be fitted within 0.5m of the
camera and at least 1.5m higher than the camera.
The construction of the housing itself is very capable of coping with secondary
strikes and no damage to the internal electronics or camera should result if correct
lightning protection is applied.
Maintenance
The unit contains no maintainable parts and in the event of failure should be
removed from site for repair.
Maintenance and repair of this equipment shall only be carried out by suitably
trained personnel in accordance with the applicable code of practice (e.g.
EN60097-19)
To maintain the validity of the certification only components supplied by Bosch
Security Systems shall be used.
On Site Inspection
It is recommended that the equipment be inspected on site every six months to
check mounting bolts for tightness, security and any signs of physical damage.
Inspection of this equipment shall only be carried out by suitably trained personnel
in accordance with the applicable code of practice (e.g. EN60097-17)
