Magnets of the USR and US/R type are equipped with a dual loop heat exchanger cabinet. On its primary side, the dual loop heat exchanger is connected to the process water and has two secondary cooling circuits. One cooling circuit is used for the gradient coil cooling and one for the compressor of the magnet refrigeration, which is located in the lower part of the cabinet.

The cooling circuit of the magnet refrigeration is continuously running while the operating state of the cooling circuit for the gradient coil cooling is controlled by the operating state of the MR instrument. The circuit is turned on automatically as soon as the gradient amplifier is switched on. Operating the MR instrument without gradient coil cooling is not allowed. During normal operation, no user interaction is required.

The water filling level and the water flow rate must be controlled in regular intervals, see Regular Tasks and Checks and Filling Secondary Water Tank.

Magnets of the US type are equipped with an air-water chiller for gradient coil water cooling. The operating state of this cooling circuit is also controlled by the operating state of the MR instrument. It is turned on automatically as soon as the gradient amplifiers are switched on. Operating the MR instrument without gradient coil cooling is not allowed. During normal operation, no user interaction is required.

The water filling level as well as the water flow rate must be controlled in regular intervals, see the individual manual of the chiller.