What type of switch do I need?

J

josh623

Plastic

Joined

Feb 26, 2016

• Jan 10, 2022

• #1

Just need a little quick help here...

I have a KBAC 27D VFD on my grinder that I want to wire in a toggle switch that will allow me to switch from 1x speed to 2x speed on the fly. The way it works right now is there are three pins, the center pin basically connects to the pin on either side depending if I want 1x or 2 x speed.

When I called KB electronics he said I need a single pole, double throw, on/on switch. But there are so many options on McMaster that I'm not sure what specifically I need lol.

 

J

josh623

Plastic

Joined

Feb 26, 2016

• Jan 10, 2022

• #2

would this one work? Ideally it would lock to prevent accidental bumping when grinding.

I'm just not sure how the normally open/normally closed thing plays into it...

McMaster-Carr

 

O

Overland

Stainless

Joined

Nov 19, 2017

Location

Greenville, SC

• Jan 10, 2022

• #3

One like this ?
CARLING TECHNOLOGIES Toggle Switch, Number of Connections':' 6, Switch Function':' On'/'Off'/'On - 4X851'|'2GM51-73 - Grainger

 

J

josh623

Plastic

Joined

Feb 26, 2016

• Jan 10, 2022

• #4

thanks for the input... I don't think I need 6 connections, I just have 3 wires. I need a switch that will basically let me pair either wire with the center wire (i.e. like the jumper does). So I figure that would be a 2-position on-on switch, correct?

 

C

crickets

Hot Rolled

Joined

Jul 3, 2021

• Jan 10, 2022

• #5

josh623 said:

thanks for the input... I don't think I need 6 connections, I just have 3 wires. I need a switch that will basically let me pair either wire with the center wire (i.e. like the jumper does). So I figure that would be a 2-position on-on switch, correct?

Click to expand...

You don't have to use all 6. If the price/availability is better, 6 terminal one will work as well as 3 terminal one. The other thing is some of these switches are on-off-on and some are on-off. You probably want on-off type where 1 terminal is common, and either position shorts it to one of the other two.

 

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Joe Gwinn

Stainless

Joined

Nov 22, 2009

Location

Boston, MA area

• Jan 10, 2022

• #6

The VFD probably will not like switching this while in operation, and there will be smoke. How will this be prevented?

There may be a kosher way to do this on the fly. Consult user manual.

 

M

mjk

Titanium

Joined

Oct 20, 2005

Location

Wilmington DE USA

• Jan 10, 2022

• #7

If your intent is to be able to switch between 1 and 2x speed without going in and moving a jumper I think adding an on-on switch will work.
But I agree about not switching while running, in fact a power down and possibly waiting may be necessary, depending on what components are in the switched circuit(capacitor?)
Once you have installed the switch, it works, and no smoke....make a label, no make a sign, that states "No one touch this switch while connected to power" or get a locking switch with a removable key

 

C

crickets

Hot Rolled

Joined

Jul 3, 2021

• Jan 10, 2022

• #8

If there is any uncertainty about switching that thing under various states, it's better to reach out to the vendor and clarify with them.

 

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madmachinst

Stainless

Joined

Jan 15, 2007

Location

Central FL

• Jan 10, 2022

• #9

ramp it. I see teh VFD can be programmed for accel and decel with trim-pots. You just need a way to send an analog signal that corresponds to the RPM's you want. A Power Supply with 2 adjustable outputs and you have a DTSP switch with common going to VFD Neutral between PS and VFD directly. Messing with jumpers that were meant to be changed when VFD is off, while it is running is scary, and I take risks.

 

R

Rollerman

Cast Iron

Joined

Dec 18, 2004

Location

Waltham, MA

• Jan 10, 2022

• #10

Carling makes poor quality switches. plated, maybe, brass contacts
Micro Switch makes a line of very high quality toggle switches. Silver contacts.
For switching motor power level voltage and current get a good switch.

 

B

BT Fabrication

Titanium

Joined

Nov 3, 2019

Location

Ontario Canada

• Jan 11, 2022

• #11

any spdt(single pole, double throw) switch will work that closes the switch when moved to that side, lots in the automotive world at your local parts places for $10.

 

R

Rollerman

Cast Iron

Joined

Dec 18, 2004

Location

Waltham, MA

• Jan 12, 2022

• #12

Automobile switches are not rated for 120 VAC.
Be careful!

 

JST

Diamond

Joined

Jun 16, 2001

Location

St Louis

• Jan 15, 2022

• #13

Rollerman said:

Automobile switches are not rated for 120 VAC.
Be careful!

Click to expand...

The control contacts involved may or may not be on the "hot" part of the VFD. They are set and forget jumpers, so they might be without a problem, but probably they are on the I/O controller portion, which is most often isolated and at a safe voltage, The switches themselves are usually controlling low current 5V type signals

Check manual to be certain.