Page top

Lead Contents

FAQ00846 of Level Switches FAQ

FAQ No. FAQ00846

Primary Contents


With 61F-G1 Floatless Level Controller, the water level of a water supply is above the E2' height, but the pump does not operate. What is the cause of the problem and how can it be corrected?


The following items may be the cause, so check these.

Likely Causes

A power interruption occurred and the U1 Relay Unit was reset.

The U1 Relay Unit is not self-holding because of a disconnection or poor contact between the E2' electrode and its cable.


1.Momentarily short the E1' and E3 terminals of the 61F-G1 Controller to operate (self-hold) the U1 Relay Unit.

2.When the U1 Relay Unit will not operate (self-hold), replace the U1 Relay Unit. Also, check whether there is a damaged cable between the 61F Controller and electrode, and check whether the E2' electrode is coated with tarnish or oil.

3.As an emergency measure, operation can be forced by shorting the E1' and E3 terminals on the 61F-G1 Controller, however, idling cannot be prevented in this case.