Thelowest water level is safeguarded by means of a safety levelswitch B91 (switch-on blocking).The supply water level is safeguarded by the level switchB90 which has a protective function as well.
Najnižja raven vode je zaščitena z varnostnim stikalom B91 (blokada vklopa). Raven dovodne vode je zaščitena z nivojskim stikalom B90, ki ima tudi zaščitno funkcijo.