A pump left in manual will run dry. Seals will overheat and eventually fail.
The majority of submersible pump starters have a manual/automatic switch to bypass the pump controller automatic mode. Subsequently pumps are often left running long after the sump has been emptied.
Running pumps without adequate fluid overheat mechanical seals and ultimately fail. After the seals fail, fluid bypasses into the motor housing causing premature failure of the pump. Not good! This results in flooded work areas, loss of production, equipment downtime and wasted money!
Instead of using a Manual mode you should be able to start the pump in automatic mode so the pump doesn’t run dry.
A Frustrating Friday Night.
At 6pm on a Friday night I received a phone call at from a customer needing assistance. His SCADA monitoring system was generating alarms for a pump that had failed to stop during normal operation. The customer was an hour’s drive away from the pump site in South Australia (I was in Queensland) and he wasn’t keen to travel out to the site. After all it was a Friday night.
I logged into the system remotely and spent the next two hours investigating what was causing the pump to run continuously. Eventually I informed the customer that the problem could not be resolved remotely. “You are going to have to visit site.” By the time he got to site it was 9:30pm.
He called me back later and sheepishly said, “The pump was left in manual, I’m sorry for wasting your time.” The customer is a very diligent operator however earlier in the day he had switched the pump to manual mode to check its’ operation and simply forgot to change the switch back to automatic mode.
Why did he run the pump in manual? This was the only option available to test run the pump.
It happens all the time.
To reduce the water level of a sump manually operators must select manual (disabling auto control) to start the pump. After starting the pump they realise it will take some time to reduce the water level. The operator decides to leave and check the level again later.
Do they remember to return and check? If not, the pump eventually runs dry and potentially fails allowing the sump to overflow into the work areas.
At this point personnel are required to source a replacement pump, remove the pump from the sump and install a new pump. This is a frustrating and avoidable situation that cost time and money.
Surely there is a better way! Just use the Start Button!
Why couldn’t he simply push the start button while the pump was in auto mode? Surely he should have been able to just press the Start button and have the pump stop normally. When the pump reaches the normal stop condition (a level in this case), it should just stop.
Frustratingly most submersible pump controllers don’t allow manual starting in automatic mode and they have to bypass the automatic control to start the pump.
Don’t depend on an operator’s memory.
An operators memory should not form part of a control solution, it clearly isn’t a solution. Pump controls should not require human intervention under normal operating conditions. They should help by removing the possibility of making mistakes.
Operators do not intentionally run pumps dry, but to ensure the situation doesn’t occur they must remember to return before the sump empties. With a simple change to the controls this won’t happen, which will save you time, money and unnecessary frustration.
Why have Manual Mode? What is it for?
- To test the pump is working properly.
This could be during installation, or just to check on the operation of the pump;
- Pump the level down in the sump or hopper.
Maybe you need to move or replace the pump or replace a check valve;
- The automatic control has failed and you need to run the pump.
Perhaps a float switch or level sensor has failed and no longer starts or stops the pump.
Scenarios one & two are easily solved using a Start button with automatic mode enabled. In the third scenario it is sensible to have a manual option. A spring-return manual switch could be used but this will force the operator remain at the panel holding the switch waiting (and waiting, and waiting) for the pump to empty the sump. A spring-return switch will do the job but is a really inconvenient solution.
You can use a normal manual/auto switch and use administrative controls to discourage operators from leaving the switch in manual but this isn’t a fail-safe solution either. A lockable auto/manual switch could be used to enable maintenance personnel to start the pump when there are faults with the automatic functions, however this is also an inconvenient solution.
It is a matter of choosing the right option for your application. Do give the operator a Start button so that they are not forced to bypass automatic control just to do their job. By just providing a way to start the pump in Automatic mode you give them the right tool to do what they need to do. You will also reduce the damage to pumps and the frustrations that result.
The 2iB SC10 Pump Controller supports a Start input
Designing pump starters to incorporate a start function in automatic mode can be achieved with additional control logic.
Of course, we think you should use the 2iB SC10 Pump Controller for your dewatering pumps.
The SC10 Pump Controller is an economical and simple solution to ensure pumps can be started in automatic mode with designated start input for connection of the panel start button. This enables the pump to be started anytime in automatic mode.
Starting the pump in automatic mode guarantees the pump will stop when it’s normal stop condition is reached. Normal stop conditions include detection of pump snoring or a low level float switch which will ensure the pump will not run dry for extended periods.
The 2iB SC10 has been designed by 2iB based on feedback from submersible pump operators. It supports a number of operating modes (see link below) so the pump starter can be used for multiple applications with or without floats.
The SC10 Pump Controller will save time and money!
SC10 Pump Controller Features
Pump current reference display
Analogue input scaling input via dip switches
Quick push button set point setting
Multiple input control options
local and remote stop and start capable
Multiple alarm out selection.
Set point inputs for external buttons.
Multiple Control Options
Timer start, Snore stop
High level start, Snore stop
High Level start, Low Level stop
Push button start, Snore stop
Push button start, Low Level stop
Push button stop, Timer start
Push button stop, High level start