TECH TIP
TECH TIP
Contactor Trouble Shooting
David Duckworth
David Duckworth is the Director of Training and Development at Commercial Kitchen Parts & Service in San Antonio, Texas.
THERE are two types of noises Electro mechanical contactors make that require two different repair solutions.
“ Chattering contactor”- The movable contact bar will not stay engaged with the stationary contacts. It is pulling in and releasing rapidly multiple times.
The problem lies within the control circuit supplying voltage to the contactor coil. Some examples of these are:
a) Lower voltage supplied to the coil than it is rated for b) An intermittent drop in the supply voltage c) Slow opening and closing contacts on a solid state control board d) Door reed switches that are failing
This is the area you will need to trouble shoot. You do not have to replace the contactor in this case unless there are other signs of wear.
“ Buzzing contactor”- The movable contact bar is pulled in to the stationary contacts, but the coil is struggling to hold the contact bars armature down causing the contactor to buzz.
The problem is the contactor itself. It is simply wearing out. The only solution is to replace the contactor. Be sure to use the correct rated contactor when replacing.
FLA = full load amperage for motor duty only.
Resistive = full load amperage for none motor applications. e) Loose wire connections
SPRING 2016
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