GE OPTIMA MR360 Service Training page 139

RF amplifier, gradient amplifiers and gradient power supply are all water-cooled in SV
system cabinet. Leak sensors are used to detect if there is leakage happened on any water
pipe connectors.
Leak sensor is composed of two parallel wires that terminated by a 8.3MOhms resistor at
one end. The electroconductive part of the wires are exposed every one centimeter. The
other end of the leak sensor are connected to the cabinet monitor.
• If the leakage sensor are broken, the resistance between A and B will be greater than
50MOhms. This will be labeled as SF (Sensor Failure) on the cabinet monitor.
• If any leakage happens, because the coolant resistance are less, the resistance between
A and B will less than 3MOhms. This will be labeled as LK (Leakage) on the cabinet
monitor.
• If there is no SF and LK, the resistance between A and B should be equal to 8.3MOhms.
According to three different resistance values, cabinet monitor can identify three status.
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