©AM SENSORS LTD
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AMS-S-082/DS/09.2016 (ISSUE 2)
6. Commissioning
/ Functional Testing
Electrical Connections
5.4 Earthing Flameproof Versions
The Flameproof Float switch has 2 earthing points, the internal earth point is
provided in the float switch lid, while the second earthing point is external to
the float switch on the body.
Both earthing points have an earthing tag secured in place with a Stainless
Steel M6 socket headed bolt and spring washer.
All switches should be earthed correctly to maintain the ATEX certification.
Functional Testing – FS1790
Before the float switch is installed, it can be checked for functionality using a
continuity checker or ohmmeter.
i)
Assembly the float switch body and float arm assembly, temporarily
using the shipping bolts to hold it assembled.
ii)
Remove the terminal cover lid as described in section 5.2.
iii)
Connect the continuity checker to the wires for the switch (switch
configuration as shown in section 5.3).
iv)
Lift the float in an upwards direction and confirm that the switch
changes state.
v)
Let the float gently return to the original position (horizontal to the float
arm baffle plate) and confirm that the switch has changed state.
Commissioning
Once installed the ATEX Group I Horizontal float switch can only be tested from
the vessel internally or tested with the liquid level rising / falling in the vessel. It is
therefore recommended that the FS1790 float switch is functional tested before
the switch is installed in the vessel.
WARNING:
When the FS1790 is being used in an explosive atmosphere, any supplies to
the switch MUST be isolated before removing the float switch lid.
Earthing Tag
Float Switch Lid
Float Switch Body