MAW Solutions Ltd Hanworth TW4 5PY Phone: 01273 493343 Email: firstname.lastname@example.org
A new pump controller!!
Although the Dual Controller has proved very successful and reliable during its 4 or 5 year life, Davies Craig have now (march 2015) launched an updated version with a number of new facilities and improvements. First and most obviously the new controller has a real time display of coolant temperature, water pump operation, fan operation, plus the ability to report various alarm conditions in case of any cooling system problems. Also, the engine temperature can be set to one of 9 settings at the push of a button. And not only will the new unit control all the larger pumps in the range (EWP80, EWP115, EWP130 and EWP150) but now also the 24-volt versions.
The new controller uses the same sensor to measure coolant temperature, and translate this temperature into a variable voltage. Then, the higher the temperature, the greater the output voltage, and so the faster the pump rotates, and the greater the volume of coolant flow.
The LCD Controller is backwards compatible - it will replace a previous dual controller simply by plugging it into the old socket. It is available either on its own or in combo packs with one of the pumps, and the even better news is that the prices have not changed.
The LCD Controller is available both as a separate controller and also included with pumps in the various combo packs.
Why a controller?
A pump controller is only required in installations where the electric pump is the only pump. If the electric pump is installed to assist a mechanical pump, then it should be controlled by a switch. Basically, the Dual Controller is performing three main functions. Firstly, it is acting as a thermostat by limiting coolant flow until the engine has warmed up - initially pulsing the coolant, and then gradually speeding the pump up. Secondly, once the engine has warmed up it varies coolant flow to maintain engine temperature at the preset level, so minimising wasted pump power and optimising engine operating conditions. Then thirdly, when the engine reaches 3 degrees above its target (set) temperature, it will operate the electric cooling fan (via a relay).
Key Features of the new LCD Controller (part no. 8000):
LCD display including coolant temperature and set temperatures
Flashing EWP logo signifying pump operation / coolant flow
Rotating fan symbol indicating fan operation (cuts in at 3degC above set point)
9 set points from 60degC to 100degC in 5 degree steps, achieved by simple push button
Factory set temperature is 85degC
Automatic pump run-on after engine shutdown to eliminate heat soak problems
Flashing indicator if supply voltage is too high or too low
Audible alarm if coolant temperature is below 40degC after 5 mins engine run time
Audible alarm if coolant temperature rises more than 10degC above set temperature
Audible alarm if coolant temperature exceeds 100degC
Weight only 90 grams, can be readily mounted in the dashboard area
The Controller needs to be mounted inside the car, away from the harsh under-bonnet environment, and is supplied with a sensor in a waterproof housing, and a colour-coded wiring harness for connection to the pump and fan. The sensor has a 1/4” BSTP thread which can either be screwed directly into a suitably tapped hole in (eg) the thermostat housing, or mounted into the top hose adaptor which is supplied in the box.
In operation, the Controller begins to pulse the EWP (10 seconds on, 30 seconds off) as soon as the engine is running, to avoid any risk of local hotspots developing. When the engine warms to 20 degC below the Set Point, the pulsing changes to 10seconds on, 10 seconds off; and then as the Set temperature approaches, the EWP goes into continuous run mode, with the speed of its running determined by the Controller so that Set Point temperature is reached and then maintained.
To reduce heat-soak effects after engine shutdown, the Controller automatically keeps the pump (and fan) running at full speed for 3 minutes, or until the sensed temperature is reduced to Set Point - 10 degC.
Installation note: The green/black wire from the Controller which operates the fan carries a negative (chassis) polarity when it operates, rather than a positive (live).