Dry run is one of the most common reasons a submersible motor burns. When the water level in the borewell drops below the pump, the motor keeps running without water and overheats. Without protection, by the time anyone notices, the winding is damaged and the motor has to be pulled out and rewound. Here is how dry run protection in a BTCO starter stops that, and how to set it.
What is dry run?
A submersible pump is cooled by the water flowing past it. When the borewell’s water level falls, often in summer or after the pump has run for many hours, the pump starts sucking air instead of water. The motor keeps running, but with no water flowing past it, it heats up fast. Run it like this for long enough and the winding burns.
How BTCO dry run protection works
The MPAU inside every BTCO 3 phase starter keeps watching how the motor runs. When the borewell runs dry, it recognises the dry run and switches the motor off before it overheats. The display shows Dry Run Trip, so you know exactly why the motor stopped.
The motor restarts by itself: the dry restart time
After a dry run trip, the borewell needs time to fill up again. On a BTCO starter you set a dry restart time. After a dry run trip, the starter waits for that time and then starts the motor again on its own. If the water has come back, the motor keeps running; if not, the protection trips it again. Set the time to suit how fast your borewell refills.
Not the same as the cyclic timer: watch the short video cyclic timer or dry restart time, what is the difference?
How to set dry run protection
Turn on dry run protection on the starter and set the dry restart time. Our video shows it step by step:
Your starter shows “Dry Run Trip”. What now?
The protection has done its job: the motor was switched off before it could burn. Usually the water level in the borewell has dropped. Let the starter restart after the dry restart time, and if it keeps tripping, the borewell may need a longer rest, or have your borewell technician check the pump depth. This video explains the message: Dry Run Trip error (English), Kannada, Telugu.
Know about dry run on your phone
With the BTCO GSM Module fitted, a Dry Run Trip comes to your phone in the BTCO Starters app, with the reason. You know when the borewell runs dry without going to the field, and you can switch the motor ON or OFF from your phone. What is a mobile starter?
Which BTCO starters have dry run protection?
All BTCO 3 phase starters, DOL, Star Delta, Combined DOL and Combined Star Delta, through their MPAU unit, and the Single Phase starter. The Domestic single phase starter also stops the motor when the sump is empty, with its water level controller. Not sure which starter you need? Read DOL vs star delta.
Dry run is one cause of burnt motors; overload, voltage problems and single phasing are others. Read why submersible motors keep burning, and how to stop it.
Frequently asked questions
What is dry run in a submersible motor?
Dry run is when the pump keeps running after the borewell’s water level has dropped below it. With no water flowing past to cool it, the motor overheats and can burn.
How does a BTCO starter protect against dry run?
The MPAU inside every BTCO 3 phase starter recognises a dry run and switches the motor off before it overheats. The display shows Dry Run Trip.
Does the motor start again by itself after a dry run trip?
Yes. You set a dry restart time on the starter. After a dry run trip it waits for that time, so the borewell can refill, and then starts the motor again on its own.
My starter keeps showing Dry Run Trip. What should I do?
The protection is working: the water level in the borewell is dropping. Give the borewell a longer rest with a longer dry restart time, or have the pump depth checked. Our Dry Run Trip video explains the message.
Can I get a dry run alert on my phone?
Yes, with the BTCO GSM Module fitted. Dry run and overload trips come to your phone in the BTCO Starters app with the reason.
Protect your motor with BTCO
Call or WhatsApp us with your motor’s HP and your power supply, or visit your nearest BTCO Starters dealer. More answers in our motor starter FAQ.
More videos on our videos page. Follow BTCO Starters on YouTube, Instagram and Facebook.
