Function - Nilfisk-Advance MH 3M Service Manual

If the machine and the power supply are working correctly the following will happend during start up.
ON/OFF switch
If the machine and power supply is OK, the following will happen doing start up:
When the main switch S1 is turned on to cold (or hot) water mode the control transformer
transforms the supply voltage into 24 VAC, which is supplied to the main circuit board. In
the main circuit board the 24 VAC is transformed into 5 VDC.
Once the main switch S1 is turned on to cold or hot water mode the machine runs a "self-
test". All LED's lite up for one sec.
After the self-test sequence, the motor will start (K1 closes) and the pump will build up pres-
sure until cut off is reached. Once cut off pressure is reached the pump will switch to by-
pass mode for 20 sec. before it stops.
PA (pressure activated) models gets a "stop signal" from the micro switch.
Once machine has started up the status indicator lights up the green light on the plug icon
only and the pressure gauge shows max. pressure. Now the machine is in stand-by in cold
water mode. When the spray handle is activated, the pump will start up.
By switching to hot water mode the machine remains in stand-by mode. When the spray
handle is activated, the pump will start up, and if the A3 is set higher than actual water out-
let temperature, B2, B4, B6, B8, B9, EXH is closed, T2, M2 and Y1 will be powered, (M2
starts 2 sec. before Y1 is powered in order to ventilate the combustion chamber before
spraying in fuel) and the combustion will start.
SM_MH 3M_4M Ver.1.2_May 2016

Function

Cold water mode
Hot water mode Thermostat
Detergent dosing valve
ECO—mode:
EcoMode for low fuel con‐
sump on hea ng stage at
60°C.
Suction from pump
Detergent
Connected to water tank
D
MH 3M
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