Our RBT hand throttle is fitted with an 8 pin DIN plug which is inserted into a corresponding 8 pin socket. The plug should be correctly aligned with the socket before it is pushed in.
We have found that if the plug is forced into the socket with incorrect alignment it is possible that a short circuit can occur which will blow the fuse tracks on the controller itself and / or damage the pot track around the zero speed point resulting in intermittent behaviour at low speed.
There are 7 possible ways to insert the plug into the socket. 1 of these is correct, 2 will result in damage, and the other 4 have no effect apart from bending the pins.
There are two modifications that can be done to protect against the damage.
1. Fit a 1N4001 diode to the yellow wire connected to the reverse switch. This modification was introduced into production in October 2019, all RBTs with the label RBT – xxV have this done.
2. Fit a 50mA self-resetting fuse to the blue wire from the pot. This modification is being introduced into the CLM chassis lead and the part number changed to CLM-807 which can be identified by having red heatshrink tubing around the DIN socket.
A diagram showing the modifications is below.
The third [or should it be first?] way to prevent damage is of course to take care to get the alignment correct and not to force the plug home if it meets resistance.
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