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McDonnell & Miller General Catalogue Industrial Controls

McDonnell & Miller Series PS-851 – Probe Type Low Water Cut-Off

120V/24V Models available
Green LED indicates power On
Red LED indicates Low Water
Test button
Meets requirements of ASME Standards CSD-1
No lock out with loos of power if probe is in water
20,000 ohms probe sensitivity

The McDonnel & Miller Series PS-851 probe type LWCOs provide protection against low water conditions. The PS-800 is for commercial and industrial applications. These controls are fully CSD-1 compliant. Furthermore they are primarily used as LWCOs on hot water heating boilers. If you need a different model other than those listed, please contact us at

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