Fitting a soft start module to Dewalt DW745 table saw

[carpenteire2009]

Hi
I'm bit stuck on my latest project, I'm hoping someone here with more electrical know-how can help. After reading some articles on retro-fitting soft start modules to power tools I decided to track down a suitable part for my own Dewalt DW745 Type 4 table saw. As anyone who has this saw will know it is a very capable machine but the initial kick start is off putting and I've never got used to it, despite 6 years of ownership. I tracked down (what I hope) is a suitable module, branded CX-SS 24A/ 250V. This is higher amperage than what I ordered but I hope this won't affect the operation. There are a number of youtube videos that illustrate the fitting of a similar module to this very table saw and other Dewalt variants, however the wiring arrangement and schematic stamped on the module I have is different so I am wary of slavishly following instructions for a different product. The schematic on the module case is difficult to see from the photo so I've transcribed it and a "schematic" of the actual power switch, please see photos below.

In essence, incoming power cable (line in) is connected to pins 13 and 23, with noise reduction capacitor connected ac cross these pins also. A thermal overload reset button is wired in line from the line in neutral to pin 13.

Line out neutral and live from the motor are connected to pins 14 and 24 respectively.

I have spade connectors/ piggy back connectors, crimper and cable necessary to make the relevant connections all I need is some simple directions, if anyone could help I would be very grateful! Thanks for taking the time to read this.

 

[point5clue]

Hi Carpenteire,
I’ve done the same with a similar module. Best thing I ever did. I definitely took some before photos. I’ll check if I took an after photo. It might be a day or two before I can clear enough space to open it back up but I’ll see what I can do over the weekend. I just followed a YouTube vid too

 

[carpenteire2009]

Thank you point5clue, maybe someone else might chime in with some advice before then I wouldn't want you going to the bother of opening it up!

 

[point5clue]

Found the photo - typical me - I'd taken an 'after' but not a before so it would have been no use if it didn't work.

this was what I bought - yours looks pretty similar
https://www.amazon.co.uk/gp/product/B08N6B76PZ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
Not available now, but the version without the connector blocks is.

If you zoom in you can see where the wires go. Hope its of some help.

 

[carpenteire2009]

Thank you so much for that point5clue, I'll have to study that this evening and hopefully get it it up and running on Saturday!

 

[carpenteire2009]

I'm struggling with that photo, unfortunately, anyone care to decipher the schematic on the module for me, all at my own risk of course!

 

[phil p]

Hi,

I thought I had seen something on YouTube a while back on this.

If you check out Tomas‘s video on his Channel “Casual DIY” he shows you how to do this, however his is an Evolution tablesaw but I’m sure it will basically be the same.

If you get it sorted I would appreciate if you could post the difficulty in the process as I have the Dewalt and may do the same as I agree that it’s a beast on the start up!

 

[point5clue]

Hi Carpeneire, sorry - one of those weekends - my better half's birthday and Mothering Sunday - didn't get a chance to touch the laptop much let alone the tablesaw!

The two videos I used are below - the first one has a better view of the wiring, and I reccomend using the spade connectors the way he does, but I agree with he second chap about where the place the neutral wire. Hope this helps.

 

[carpenteire2009]

Thanks for this, I may not get a chance to look at this for a couple of days with busy family stuff going on. I appreciate all the help so far.

 

[carpenteire2009]

I thought it only fair to report back here, especially after all the helpful advice that was offered. Unfortunately I had to admit defeat in the end! I couldn't make head nor tail of the wiring diagram and the videos posted showed a soft start module with a different wiring layout plus one of the videos showed the saws capacitor wired in differently to that on my machine. To make matters worse I can't access the internet in my shed so I was trying to watch the videos at the kitchen table and take notes before heading out to the shed! The saw switch was disassembled and the saw out of action for a month and I was reminded of this each time I tried to do anything else in the little piece of heaven I call my workshop! I called it a day and put it all back together last week and I'm now back to using the machine as the makers intended, it was worth a punt and I'm only down the cost of the component. Thanks to all anyway.

 

[Sandyn]

I think if you wanted to start again and did it step by step, people on here could get it working for you. Would need better pictures of your saw wiring, then create a wiring diagram for you based on your wire colours and the Soft start module, But would understand if you couldn't be bothered. I often start things and the effort becomes much more than it's worth.

 

[sams93]

I am about to do the EXACT same thing to my Excel table saw. I've just purchased one of these which will come on monday,

(Soft Start Module Motor Starter XS-16/D3 upgraded XS-12/D3 Universal | eBay)

I would be keenly interested in understanding better how to install it, as it is quite difficult to tell from the various photos avaliable.

It would be handy if those who have successfully done this before could guide us through the process!

Thanks

 

[Silfi]

The simplest option is to make an extension cable with the module in the back box of a 13a socket outlet. I use it with my table saw (need to hold in the NVR switch for a second or 2) and router. It makes a huge difference to the starting noise and jerk.

 

[sams93]

The simplest option is to make an extension cable with the module in the back box of a 13a socket outlet. I use it with my table saw (need to hold in the NVR switch for a second or 2) and router. It makes a huge difference to the starting noise and jerk.

I plan to wire mine into the switch of the table saw itself, but that is because I tend to move it around so it would be plugged into different outlets at different times.

it would be great to know how exactly you wired up yours in though into the back box, it’s the wiring arrangement that I’m confused about.
thanks

 

[Sideways]

I'm going to take a wild guess here, which I really shouldn't and I won't be held responsible for it, but this might just give you a clue:
First : a no volt release switch isn't designed to work with these soft starters. When you start the saw, you may well have to hold the green button in while the saw speeds up. Only once it's at full speed will the current through the saw be enough to hold the NVR's magnetic switch closed and keep the power on.
Second : I'd put the soft start between the NVR switch and the motor, not between the mains and the NVR switch
Third : The soft start is a 3 terminal device, yes ?, one terminal will be mains Live into the device, one will be mains Live out to the motor (this is the the one that will start low and ramp up to full voltage). The third terminal needs to be connected to neutral. This acts as a reference only. The module is essentially a switch that pulses the live output while it is soft starting. It needs to have a contact to neutral to know when to pulse but this third wire carries very little current.
Neutral and earth are left unchanged, connected straight from the NVR switch to the motor, you just need to connect the third leg of the module to the Neutral at one end or the other without breaking the neutral connection.

Why does the module diagram look a little more complicated than this description ? It's probably designed as a generic device. In the UK we are very clear about our Neutral wire, which is connected to earth at the point where the mains comes into your house, and the Live wire which has an alternating voltage relative to the Neutral.
In Europe, plugs aren't polarised and live / neutral can be either way round. To be safe in a piece of european machinery, they will need a 2 pole switch as you have no idea which is the live wire and therefore have to behave as if they are both live. This isn't a bad safety feature. We use 2 pole isolator switches for safety too, in things like immersion heater, shower and cooker switches. But UK wiring done correctly always knows which wire is the live, so we only switch the live wire in socket outlets and light switches.

My description is based on the way a simple thyristor or triac speed controller is wired. I think that's all these soft starters are - a speed control - but there's no knob, just a circuit inside the module that is equivalent to the knob being steadily turned up from 0 to full speed as soon as power is connected.

Good luck and don't trust a word you read on the internet !!!

 

[Stevekane]

I am about to do the EXACT same thing to my Excel table saw. I've just purchased one of these which will come on monday,

(Soft Start Module Motor Starter XS-16/D3 upgraded XS-12/D3 Universal | eBay)

I would be keenly interested in understanding better how to install it, as it is quite difficult to tell from the various photos avaliable.

It would be handy if those who have successfully done this before could guide us through the process!

Thanks

Hi, Im watching this too and would like to fit one to my Excell Site Saw which starts with a vicious kick, and I think it would probably be good for the saws gearing too,,
Steve.

 

[sams93]

I will try to document well as I do it and post the progress. I’m planning to fit it motor side as discussed in the prev posts.

 

[Stevekane]

I will try to document well as I do it and post the progress. I’m planning to fit it motor side as discussed in the prev posts.

That would be excellent Sam, many thanks,
Steve.

 

[Stevekane]

Just as a matter of intrest but I think Ive seen different spec modules being used, from memory, but I might be wrong, 15 amp or 25amp and Ive also seen videos where the saw starts really softly building up speed over 2 or 3 seconds wheras others seem to still fire up rather suddenly,,is there an ideal rated module for certain motor sizes perhaps?
Steve.

 

[MorrisWoodman12]

There looked to be a total lack of insulation over the connections in that first video. Please don't forget to insulate thoroughly preferably with two layers of heatshrink tubing.