Float Switch; [A] Explanation Of Operation; [B] Cleaning; [C] Float Switch Check Procedure - Hoshizaki KMD-410MWH Service Manual

5. FLOAT SWITCH

[a] EXPLANATION OF OPERATION

The float operates 2 switches within the float switch. The lower switch (black and blue wires)
is used for low water safety protection, initiating the freeze cycle refill and terminating the
freeze cycle. The upper switch (black and red wires) is used to terminate the freeze cycle
refill only. Refill will last until the upper float switch closes or the 1 minute countdown timer
ends, whichever comes first.

[b] CLEANING

Depending on local water conditions, scale may build up on the float, float switch shaft and
inside the housing. Scale on the float or shaft can cause the float to stick causing erratic
operation. The float switch should be cleaned and checked before replacing.
First, disconnect the float switch connector from the control box and remove the water tank
and pump motor bracket together from the icemaker. Twist the mechanical lock inside of the
pump motor bracket and remove the float switch. See "V. 15. FLOAT SWITCH." Remove
the retainer clip from the shaft and slide the float off the shaft. Soak the switch assembly in
ice machine cleaner. Wipe down the shaft, float, housing with cleaning solution. See "VI.
CLEANING AND MAINTENANCE INSTRUCTIONS."

[c] FLOAT SWITCH CHECK PROCEDURE

Before replacing a float switch that you suspect is bad, make sure the float switch has been
cleaned. This procedure will help you verify your diagnosis. The float switch has three wires.
The black wire is common. The blue wire is for the lower float switch contact and the red
wire is for the upper float switch contact.
1) Disconnect the black float switch connector from the control box.
2) Drain the reservoir water.
3) Turn the control switch to "ICE".
4) As water fills the reservoir, the float switch contacts should close. Check continuity of the
lower float switch contacts using the black and blue wires and the upper float switch
contacts using the black and red wires. With the float positioned all the way up, both float
switch contacts should be closed. If either float switch contact fails, the assembly should
be replaced.
5) Turn the control switch to "OFF".
6) Drain the reservoir water.
7) As water drains, the float switch contacts should open. Check continuity of the upper float
switch contacts using the black and red wires and the lower float switch contacts using
the black and blue wires. With the float positioned all the way down, both float switch
contacts should be open. If either float switch contact fails, the assembly should be
replaced.
8) Reconnect the black connector to the control box when finished.
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