The PM Guard pre-pressure safety device should be installed when using a SCALA2 pump behind the water meter according to legislation. The PM GUARD ensures that when the pre-pressure falls below a certain level, it automatically switches off the pump. When the pressure reaches the normal level, the SCALA 2 becomes operational again. Applicable in single-family houses up to 3 floors and 8 taps, apartment buildings, holiday homes and in agriculture/horticulture. The PM GUARD complies with the Dutch Water Worksheets (NEN1006 (WB) 4.3). Switch-off pressure: 0.5 bar. Switch-on pressure: 0.6 bar. Max.operating pressure: 16 bar. Connection: 1’ external thread. Comes standard with 1.5m Schuko power cable, 0.5m Schuko cable for connection to the Scala 2, stainless steel T-piece and pressure sensor with 2m cable.