New Controller #8001

MAW Solutions Ltd    Hanworth TW4 5PY     Phone: 01273 493343   Email: info@mawsolutions.com

Note: This #8001 model of controller was introduced in autumn 2017 to replace the previous LCD controller.  It has enhanced functionality, as detailed below, and is backwards-compatible so that it can be fitted as an upgrade into existing controller sockets.

Davies Craig’s new #8001 controller will manage engine temperatures in a wide variety of vehicles, via all the electric pumps in the EWP range, both 12-volt and 24-volt models.

Like previous generations of controllers, the unit is mounted within the vehicle, and connected via wires to:

  • a temperature sensor mounted in the top house, thermostat housing etc
  • the electric water pump
  • the ignition switch and chassis
  • direct to the battery, to allow pumping to continue after ignition shut-down.
  • the electric fan relay
  • a red warning led which is mounted on the dashboard.

The controller’s task is to monitor engine temperature, ensure that the volume of coolant being pumped around an engine and through the radiator is varied according to how warm the system is, and how hard the engine is working, and also to flag up any alarm conditions. 8001 The controller uses a thermistor-type sensor probe located inside the engine’s water jacket (eg inside the thermostat housing) to sense engine 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. . 

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 controller is performing four 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). Finally, when the engine is switched off the pump (and fan) will run on to prevent any hotspots from developing.

Target temperatures can be set in the range 60 - 100 deg C , and the screen will display actual temperature. The setting is retained even when the battery is disconnected - a new feature which should please race car drivers with battery kill switches!  There is also a new override feature to allow the pump to be run at full speed during system bleeding after installation.

Audible and visual alarms will be triggered when:

  • Coolant temp doesn’t reach 40 deg C within 5 mins of startup.
  • Coolant temp exceeds set temperature by 10 deg C or more
  • Coolant temp exceeds 100 deg C
  • Voltage supply is either too high or too low
  • EWP operation error
  • Temperature sensor error.

Note that the audible alarm can be switched off, without affecting the alarm display.

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 up to 3 minutes, or until the sensed temperature is reduced to Set Point - 10 degC,  .

Please feel free to phone us on 01273 493343 to talk about your application.