Grundfos timer and thermostatic control accessories are designed only for use with specified grundfos series up circulators installed in indoor hot water service systems. Applicable series up models include all single speed up 10 15 1 phase 115 volt 60 hertz pumps with date codes of 0528 and higher. Where the devise could break the 110 120 neutral wire as served it should be installed there at ohms the use is seldom limited by pump where 240 0r muilti phase wiring the use is as said set by the pump devise and must limit at phase where the stat is poly tube set the ground free should be wired to the source ground of the.