Converting A Jet 1340 Lathe To A Variable Frequency Drive Using A Teco L510

mksj said:
I think you are talking about 3 wire control with regard to momentary switches, the default is 2 wire controlled which uses maintained switches (page 4-34). The issue with 2 wire controlled using maintained switches, is that if there is a power outage or you accidentally leave lever in the forward/reverse position, the machine will restart which presents a safety issue. Using the VFD, you usually would gut the old control board, since it would not be used giving you space for other options. On a lathe, there is usually a power relay that latches either with a button or when the spindle direction switch is in the stop position, this prevents a restart. An E-Stop would normally interrupt the connection to the COM input terminal (or the power relay), the danger with maintained switches, is that the late would restart when the E-Stop is reset if a power relay is not used. Killing the power to the VFD with the E-Stop or via a contactor is not recommended in this setting, and a simple power reset relay is more optimal.

The Teco does have a feature which prevents auto restart, on page 4-58 : 07 - 00 would be set to 【0】: Momentary Power Loss and Restart disable. You could try this with 2 wire control and see if that works. One of the inputs can be reprogrammed to JOG if needed. I have some schematics for relay based controls, but it is a bit more complicated.

What is the specific Jet model you have and what functions do you want?
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my lathe is a jet model GHB – 1340
as far as functions I only need the forward stop reverse switch on my carriage wired in everything else I got it figured out also I did install a relay on the single phase power input and configured it to stop a restart until a button is pushed, everything else I can control from the VFD itself since the way I mounted it gives me access to the VFD control panel while I'm operating the lathe.
One question though, if I'm using the two wire control how does that work with a three position switch (forward, stop, reverse)?
 
In the stop position both switch contacts are open.
 
There are 2 sets of contacts in the switch. In forward, one set is closed, in reverse, the other set is closed. In the stop position both sets are open. It is literally wired just like the diagram on page 4-33. There are 3 wires going to the switch, one common, and the other two go to forward and reverse contacts.
 
JimDawson said:
There are 2 sets of contacts in the switch. In forward, one set is closed, in reverse, the other set is closed. In the stop position both sets are open. It is literally wired just like the diagram on page 4-33. There are 3 wires going to the switch, one common, and the other two go to forward and reverse contacts.
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like I said brain-dead moment I forgot about the common, my thought pattern was stuck in DC voltage :).
And thanks a bunch.
 
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