HAKO 7580.02, Service Booklet

Page: 71 / 116

Foil 71
9.2.3 ZAPI Controller
8) VMN HIGH
Test in rest state;
Voltage at VMN terminal normally equals 50% Vbatt if contactors are open. If this voltage is
excessive (> 70% VBatt), an alarm will be output. Possible causes :
a) One of the direction contactors is permanently closed due to mechanical blocking
or permanent activation (incorrect wiring of contactor coil)
b) Short-circuit between field and anchor coil of the motor
(disconnect cable at VMN terminal, switch on, Fault disappears, repair motor)
c) Incorrectly connected motor cable (check field and anchor wiring)
d) Power element of controller defective (suppressor or brake diodes short-circuited)
disconnect cable from VMN terminal, switch on, fault persists, replace controller