WCP Magazine Dec 2014

Our controllers are able to operate in ambient air temperature up to 40C. By this I mean that the control
will operate normally even if the air temperature during the day reaches 40C. The control will also operate
happily in temperatures to minus 5c. Electronics are far better coping with cold than heat.
As part of our testing a control was fitted to a pump running at maximum for long periods the Temperature
Controller
I have in the past covered how a controller can add value to you
system and very quickly return the cost on investment.
As with many things not all controls are created equal. The Spring range of controllers have a number of
unique protection systems built in. These are there to protect the control, system and you the user.
If your pump develops a fault then the controller offers the first level of protection. With a Spring controller
if the pump becomes disconnected the controller shows 'PS' because it appears the same to the controller
as if the pressure switch has opened. Crucially the controller will not continue to drive current at full power
to the pump, but re-test every few seconds. This minimises the risk of a dangerous fault developing (as
could occur from a loose/moving connection touching down to earth) because the controller is limiting the
energy.
If the pump takes too much current the controller will shut down. A pump may take too much current if it
becomes faulty. Alternatively too much current will be drawn if the pump negative wire should short to
earth. In this instance the controller will shut down the output to protect itself and the wiring. It will display
the message 'OC' to indicate this.
For more information please see: http://www.springltd.co/node/41
Reverse polarity protection
We fit a reverse polarity diode to the power supply circuit on the PCB. The diode is fitted so that in the
event of a miss-wire (reverse polarity) it will blow. In this way we are able to protect the sensitive parts of
the control and effect a repair if needed. We see a handful of controls come back to us having been
miss-ired in any one year.
Fitting a correctly rated fuse will provide additional protection to the control in reverse polarity situation. As
the current passes the wrong way around the circuit with the fuse now on the output part of the circuit, it
will still blow helping to prevent further damage to the control.
Heat Protection
As previously mentioned copper is not a perfect conductor of electrical current. A small amount of current
will be turned into heat, you will notice the pump motor, cables and controller can be warm to the touch
after a days use.
The Spring range of controllers are designed to return unused current back the battery and also have a
means of dissipating heat to prevent access temperature build up on the PCB.
In testing we push the control to extremes well beyond that seen in normal use.