Fitting a soft start module to Dewalt DW745 table saw

[Stevekane]

Back to your original questain John, I asked the vender I bought my soft start module if they would work with induction motors and thet said they wouldn't,,but maybe there are better slightly different ones out there that would suit,,
Steve.

 

[deema]

Nice rabbit hole this! From memory of the standards, all the devices I’ve seen so far should not be sold in the UK, they are not compliant. Nice big lump of metal connected to the switching triac and no earth! Well, as I keep saying, if you haven’t a clue about electronics stop meddling, it’s only a matter of time before this kind of stuff is going to kill someone. I’m not a kill joy, just someone who has seen what happens when people have a go with electrics.

 

[John Brown]

At the moment I have 2 130ah batteries in series, an Epever MPPT charger, a 510w panel and I'm picking up a Giandel 4000w inverter. I think the batteries may need adding to at some stage. The price of inverters seems to massively jump above 3kw. One bad thing about the inverter is the standby current, but maybe that goes with the increased price.

 

[sams93]

At the moment I have 2 130ah batteries in series, an Epever MPPT charger, a 510w panel and I'm picking up a Giandel 4000w inverter. I think the batteries may need adding to at some stage. The price of inverters seems to massively jump above 3kw. One bad thing about the inverter is the standby current, but maybe that goes with the increased price.

Keep us posted as to how you get on!

What wattage are your machines?

 

[clogs]

a friend *small organic farmer* has just replaced the Gell batteries for his 3kw system *totally off grid* the cost was just over €3000euros....
they look like huge truck batteries but designed for solar use....didnt notice how many tho....*8*....?
seemed a lot of money for them but they have done 10 years hard work...
they get worked to death......they drive his freezers and his small cabin during the night.....
the fridges n freezers are in the shady shed but they suffer as night time temps are around 26-28º

I want to do the same but 7.5 -10KW......not sure of the cost for batts....bought direct from china but thinking around 12 - 13,000euros....
I was told u need at least 15% more battery capacity than u'd expect....

lastly another friend has a similar system but 48v Lithium batts......they let the batts discharge to totally empty ....
they had to run a generator and a huge fan to get the system to start up from solar. ....something about electronic noise from the fan motor to help trigger the inverter....
something about the electronic safety not allowing the system to recharge.....
he now has an extra battery to stop this happening again.....
Apparently u need a laptop to adjust the inverter ?????
it's all above my head...I have to go this route but it does sound a nightmare to get it right....

 

[TomTheToolMan]

I would need a trench about 50m long, but the main problem is that the electrician won't connect is, as we are already at maximum for the incoming power. Upgrading that would cost a fortune.

Surely it is just an issue of managing your usage. When working in the shed don't have the cooker, kettle and electric shower on at the same time. Personally I would have the armoured cable put in and recognise that I have to manage usage

 

[John Brown]

Surely it is just an issue of managing your usage. When working in the shed don't have the cooker, kettle and electric shower on at the same time. Personally I would have the armoured cable put in and recognise that I have to manage usage

Indeed, but the electrician disagrees.

 

[gmgmgm]

Indeed, but the electrician disagrees.

Unless you have some very niche usage (multiple electric vehicles, fully electric heating over several building etc.) then a different electrician will probably be fine to set it up, the topic (I believe) is called "diversity" and it's pretty common. Logically, this isn't much different to running a big freeze in a shed.

 

[John Brown]

Yes. It is called diversity. My electrician acquainted with the concept.

 

[Myfordman]

I found this when looking around for diversity guidelines. it is taken from "on-site guide" as used by sparkies. but only a guide and there might be another way of looking at it as a combination of domestic installation with lightly used workshop or may JB is aiming for a more heavily used workshop? references suggested that much more of a calculated approach can be taken in non standard circumstances. Discussing with a more pragmatic sparky might be beneficial as IMHO your battery/inverter proposal is potentially fraught and underrated.


"Diversity

Lighting : 66% of total demand

Cookers : 10A + 30% balance + 5A for socket outlet

Electric showers :
100% for 1st shower
100% for 2nd shower
25% of the full load of any remaining showers

Immersion heaters : 100%

Underfloor heating : 100%

Storage heaters : 100%

Sockets & permanently connected equipment : 100% of demand of the largest load.40% of demand at every other point.

Maximum Demand

Current demand to be assumed for points of utilisation and current-using equipment

Socket-outlets other than 2A socket-outlets : rated current

2A socket-outlets : at least 0.5A

Lighting outlet : connected load with a minimum of 100w per outlet

Final circuits for discharge (fluorescent) lighting : rated lamp watts x 1.8

Electric clock, electric shaver supply, bell transformer, current using equipment of less than 5w : may be neglected

Cooking appliances : the first 10A of the rated current plus 30% of the remainder of the rated current plus 5a for any socket outlet incorporated in the cooker switch

All other stationary equipment : British Standard rated current, or normal current
OSG p95-97"

 

[Spectric]

Indeed, but the electrician disagrees.

The basis for any installation will depend upon the supply to the property, I am guessing you have a 60 amp supply and not a 100 amp supply. You cannot have an installation where you say that you can use either the cooker or the shower because the supply cannot support the load, it cannot exceed the available power and trying to get round this by stretching diversity factors is not acceptable.

A clue to your problem is the 50 metre trench, is this from the property to a workshop or outbuilding?

I don’t think that is the ‘ideal’ way to do it, but I think it might be within what’s allowed, there’s no limit to the length of a *fused* spur off a ring main.

But you can only have a 13 amp socket on an unfused spur, it is not best practice to run a spur to an external building.

You could fit a changeover switch to give either house or outbuilding and then no issues with the load.

What is the DNO fuse, the carriers are rated for 100 amps but can have a 60, 80 or 100 amp fuse fitted depending on the supply cable and it's length?

 

[John Brown]

My original question was about soft start modules. While I appreciate folks taking the time to respond, the topic has drifted. It reminds me of the old joke about the motorist asking the Irishman for directions, an getting the answer "well, I wouldn't start from here".

 

[aforjeh]

So I finally got this installed yesterday. i found this video which was very clear and matched by dw7485 wiring and amazon soft start module perfectly:



Interestingly my soft start module appeared to be the same, but the black plastic side of the body was mounted the wrong way round, so the A B C wire markings didn’t line up to anything at all! which is just one of the reasons it was sat on my bench for 6 months.

 

[Oom Koert]

Hi guys

I need some help with my mitre saw & the soft start.

2 blue & one grey cable comes from the motor. 1 blue & grey goes to the switch & the other blue is connected to the incoming power (blue)

I had the soft start connected, where the red (A) is attached to the motor- & incoming blue. Black (B) goes between blue from motor & switch.
Blue (C) from soft start to switch.

But it doesn't start at all. I'm assuming it should be wired differently, but I can't "see" any other way & scared of damaging my saw.

I have looked at the other posts & diagrams, but the soft start I have, differs from those & the wiring doesn't match the ABC connections.

Please, any help will be appreciated.

Thank you

 

[John Brown]

Update on the Giandel 4000w inverter:
Runs my Inca bandsaw, EB KGT500 saw, drill press etc. no problem. What it won't power? Tacwise staple/brad gun.
I'm guessing it's something to do with how the inverter periodically checks the load, and ramps up the output to match.
I may have to look out for a cheap cordless, as it's not something I use a lot, but can be handy.

 

[point5clue]

Update on the Giandel 4000w inverter:
Runs my Inca bandsaw, EB KGT500 saw, drill press etc. no problem. What it won't power? Tacwise staple/brad gun.
I'm guessing it's something to do with how the inverter periodically checks the load, and ramps up the output to match.
I may have to look out for a cheap cordless, as it's not something I use a lot, but can be handy.

Yes - I have a tacwise electric brad nailer and it won't run on my 1000W Honda generator. I assume it looks like a big open circuit to the protection circuit.

 

[mark-ukw]

Can I mention that if you have a CX-SS rather than a D3 then you want to use a wiring diagram like this. I used variant 2 with the twin pole switch. If you have a capacitor across the motor it should still end up across the motor.

 

[stuart little]

Thanks Sam, yes, after spending several more frustrating hours watching different YT vids, I eventually found one pertaining to my DW745 wiring, I found that there are a few variations over the years, & reviewing your 'layout' with a brain cleared of 'fuzzy ness' by watching the events of yesterday, " Eureka"- as the man said. Just remains now to get it done.

Complete failure, damn thing blew the switch. £51 from DW, £11 ebay. New switch fitted - module binned - to hell with it, I'll keep my saw as it is!

 

[tallandrew]

Complete failure, damn thing blew the switch. £51 from DW, £11 ebay. New switch fitted - module binned - to hell with it, I'll keep my saw as it is!

sorry to hear that. Here’s my circuit diagram. my saw is a first gen 745 with the 2 pole switch. I found the instructions online are a bit confusing.

 

[stuart little]

sorry to hear that. Here’s my circuit diagram. my saw is a first gen 745 with the 2 pole switch. I found the instructions online are a bit confusing.

Thanks, Andrew, at the moment it's a case of; 'Better the devil you know'. My saw's not getting so much usage nowadays, but will file your input for future ref..