KELCO D50 Calibration

Kelco D50 & D40 Level Switch Calibra on
The Kelco D50 and D40 level switches are factory calibrated to operate with the displacer or
displacers supplied with each switch. If required, the switch can be re-calibrated by adjus ng
the calibra on screw located on the top deck of the switch. The calibra on screw is an M3 Allen
head stainless grub screw secured with a lock nut and sealed with red enamel.

D50 Level Switch

The D50 level switch is supplied with two displacers. If the D50 level switch fails to operate on
a falling level, that is, fails to switch when the falling water level uncovers the bo om displacer
then the switch will require re-calibra on. It such a situa on unlock the calibra on screw lock
nut and wind the calibra on screw ¼ turn an clockwise and re-lock the lock nut. Test the switch
on a falling water level and ensure it operates properly. If it fails to switch, adjust the sensi vity
screw a further ¼ turn an clockwise and repeat the test.
If the switch fails to operate on a rising level, that is, fails to switch when the top most displacer
is covered by water it will require re-calibra ng. Unlock the calibra on lock nut and turn the
calibra on grub screw ¼ turn clockwise and re- ghten the lock nut. Test the switch on a rising
water level. If it fails to switch when the top displacer is covered by water, wind the calibra on
screw a further ¼ turn clockwise and repeat the test.

D40 Level Switch

The D40 level switch has a single displacer and switching must occur within the length of the
single displacer. When correctly adjusted the switch should change state at the bo om edge of
the conical sec on on a rising level and at the seam line half way down the straight sec on on
a falling water level. If a rising water level fails to actuate the switch when the displacer is fully
submerged recalibrate the switch by adjus ng the calibra on screw clockwise in ¼ turn steps
un l the switch operates at the correct point.
If the switch fails to operate on a falling water level adjust the calibra on screw an clockwise by
¼ turn and retest it. If required repeat the adjustment un l the switch operates properly.
Calibration adjustment screw and lock nut (M3)