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| LEVEL CONTROLS RELAYS | |
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Can the LVM level relay be used with only one electrode for tank empting? |
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The
installation is possible whenever the tank material is conductive.
In this case, the COM and MAX terminals must be directly connected
to the tank. When the liquid wets the electrode connected to the MIN
terminals, the LVM output relay energises and switches on the
draining pump of the tank. Once the liquid does wet the MIN
electrode any longer, the pump is switched off. |
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How does fail-safe technology work on a level relay? |
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For
pump control, the LVM series provides for the use of a normally open
(N/O) contact for both the emptying and filling functions. This denotes there will be no false activation of the relay should it be inadvertently de-energised and the pump will not start. This feature is generally considered a safety factor. |
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How must the sensitivity of a level control be adjusted on the basis of the liquid resistivity? |
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To
obtain excellent level control performance, it is good practice to
adjust the sensitivity to a value slightly higher than the
resistivity of the liquid to control. In applications with water
level control, such as drinking water in wells, rivers or wastewater,
the sensitivity value is normally set to 6-8kOhms. For rain or condensation (not distilled) water, it must instead be adjusted to 15-20kOhms. |
