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Warrick Liquid Level Control

The specification label from the inside of the cover of a Warrick liquid level control is visible here.

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The power supply and primary coil are 115 V. The secondary coils are 300 V.

This control switches a well pump which should start when the water level reaches the upper probe and stop when the level drops below the lower probe. Currently the pump fails to start reliably. The contacts were just cleaned. The bar holding the contacts, which should carry current to the pump motor, can be visibly displaced. Then there is a hum sound but the motor doesn't start. If the contacts are pushed open and then allowed to recoil shut, the motor starts.

Questions.

  • Can anyone explain the TYPE notation? "TYPE 1C1D1" in this case. A 1C1D0 appeared on eBay recently.

  • Can anyone explain the FORM notation? "FORM 49" in this case.

  • Listings of similar Warrick controls on eBay have secondary voltages ranging from 15 V to 500 V. What are the criteria for choosing the secondary voltage? My best guess is that lower voltages might work in salt water and higher voltages might be necessary in distilled water. Is this topic documented?
  • How is the hum sound generated? Presumeably it can exist when the motor is running but be masked by the loud motor sound. Will a new control make the same sound?
  • With the relay assembled, the end of the contact holding bar is visible but the contacts are not visible. Given that the contacts are clean, how can the contact holder be displaced without delivering sufficient power to run the motor?
  • What is meant by "PILOT DUTY" on the label? Thanks for replies, ... Peter E.
Reply to
Peter Easthope
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Does pilot duty relate to a second, preliminary pump, for clearing air from the system , priming, before the main pump will cut in? A submersible pump would not require priming unless an air/gaseous block gets in there

Reply to
N_Cook

In this case there is only one pump.

The pump is located at the well head. To my understanding it is a shallow well jet pump as described here.

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Thanks for the reply, ... Peter E.

Reply to
Peter Easthope

Reply to
Peter Easthope

. Since various moves of the contacts produce different effects (including startup) try bridging the contact terminals. If the motor starts then a more thorough examination of the contact mechanism would be in order. In particular the travel of the operating rod.

Reply to
Rheilly Phoull

My guess is this is the Warrick model number.

Likely specific to Warrick.

Relays can hum when they are energized. If powered by 50/60Hz the varying current can make the relay armature vibrate, particularly if the armature does not seat tightly.

Pilot duty is using the contacts for low current control. Some contacts are rated only for pilot duty - maybe controlling an external relay or contactor. In this case pilot duty is using the contacts for low current application and the voltage can be much higher.

Reply to
bud--

Greetings Peter, The hum could be from the motor itself because it is failing to spin. There are different schemes to start single phase motors spinning. When one fails then the motor shaft just oscillates back and forth. And the motor will hum. If you feel the motor while the humming is going on and it is vibrating then for some reason the run windings of the motor are energized but the start windings are not. The pump motor is probably a capacitor start motor. Is there a hump on the motor housing? I have seen capacitor start motors that had a failing capacitor do just what you describe, fail to start and then when switched off and then back on work. So look for a capacitor somewhere in the motor circuit. They are sometimes located at the end of the motor under a plastic or metal cap. There might even be a label on the motor stating the capacitor size. Anyway, they are cheap so if it has one replace it and see what happens. You should have an extra capacitor hanging around anyway because they do fail. My neighbor's well pump had a capacitor on a Sunday and they didn't have a replacement so I took the one out of my bandsaw and let them use it until they could get a new one. Also, even though the contacts appear clean they may not be conducting as well as you think. I just replaced the pressure switch on a compressor because even after I cleaned the contacts one pair had 3 ohms resistance while the other pair had 1600 ohms resistance. And this caused the motor to not start reliably. Eric

Reply to
etpm

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