Motor soft stareter with high IP rating?

[amberman]

We've used this lot in the past, before my time though:

http://www.softstartuk.com/product/rvs-dx-digital-soft-starter-ip65-version

I've used their panel mounted stuff which is cheap, simple and works fine.

 

[DickDV]

Regarding some earlier statements in this thread on relative costs of VFD's and softstarts, I find that some of what was said was way off the reality of current pricing.

In the world where I live, VFD and softstart pricing at 480VAC three phase, costs are similar from fractional up to about 10hp. The VFD pricing at that point rises faster than the softstart pricing until at 100hp the ratio is about 4/1 in favor of the softstart. Pricing continues to diverge above that point.

It is certainly true that the VFD is a better softstart than a softstart (no inrush current at all ) but if you don't need that level of inrush suppression and have no use for variable speed, then the softstart is often the better choice. The list of issues that a softstart avoids given in an earlier posting in this thread is excellent and pretty much covers the subject.

 

[jstolaruk]

I don't have the pricing in front of me, but I replaced two contactors and a softstart with a Powerflex 755 and realized a savings with reduced panel space - all AB equipment sized for 200hp. I remember the savings didn't occur until the 755 became available and my boss at the time was very happy. Maybe I got lucky!

 

[jraef]

150-C (43NBR) was the one I was refering to

Ok, so yes, that soft starter comes automatically with a built-in bypass, sou can install it in any sealed enclosure you like. It still has an operating ambient temperature rating of 40C, which would become the internal box temperature limit. So you still must consider the heat rejection of all components in the box and size it accordingly to have enough surface area to radiate it, and of course the ambient must be no more than about 35C max., but it is attainable under those conditions, I've done it many times without problem.

Quick and dirty "rule of thumb" is to make the enclosure have 4x the air volume of the starter itself. So L x W x H x 4, then start dividing by critical dimensions you can live with.

 

[rQx]

Ok, so yes, that soft starter comes automatically with a built-in bypass, sou can install it in any sealed enclosure you like. It still has an operating ambient temperature rating of 40C, which would become the internal box temperature limit. So you still must consider the heat rejection of all components in the box and size it accordingly to have enough surface area to radiate it, and of course the ambient must be no more than about 35C max., but it is attainable under those conditions, I've done it many times without problem.

Quick and dirty "rule of thumb" is to make the enclosure have 4x the air volume of the starter itself. So L x W x H x 4, then start dividing by critical dimensions you can live with.

Yes, ofcourse, but a VFD has mush more heat dissipation then a softstart so I would have that problem anyway I don't know but maybe we are comparing diffrent situations here, I compare IP20 softstart to IP20 VFD and in a cabinet. Maybe you compare the IP20 softstart vs IP66/65 VFD?

I don't have the pricing in front of me, but I replaced two contactors and a softstart with a Powerflex 755 and realized a savings with reduced panel space - all AB equipment sized for 200hp. I remember the savings didn't occur until the 755 became available and my boss at the time was very happy. Maybe I got lucky!

I have a listprice (no discount) on a PF755 160kW on 17300$ and a soft start 150-C201 (160kW) at 4900$,
I never use this big motors so don't know if the models are correct thought

 

[jstolaruk]

No, I know we didn't pay that much for a PF755, I recall the price closer to $10K. And I don't recall what discount schedule the company was on. This was about 8 years ago. The customer's spec, Chrysler, was that a inline and bypass contactor were required; not cheap but it would be difficult to make up that much of a difference. I don't recall the soft start part number. What I clearly recall is showing the boss the quoted numbers and he went for it.

 

[rQx]

No, I know we didn't pay that much for a PF755, I recall the price closer to $10K. And I don't recall what discount schedule the company was on. This was about 8 years ago. The customer's spec, Chrysler, was that a inline and bypass contactor were required; not cheap but it would be difficult to make up that much of a difference. I don't recall the soft start part number. What I clearly recall is showing the boss the quoted numbers and he went for it.

Yea, I believe you ofcourse, just wanted to show what prices they are on nowdays since you didn't have the prices. Ofcourse the discount is a great deal to this. We don't pay this mush either, but then also we have greater discount on soft starters then on AB VFD since we use other VFDs.

But still, I can't find a VFD that is cheaper then a softstart if I compare the 150-cXX to any powerflex. But then I haven't acounted for the contactors, and I see now that big contactors are really expensive! The contactors we use are mush cheaper since we are rearly over 30kW.

To make a long story short, there is a place for every product, no matter how mush we compare prices

 

[jstolaruk]

And I apologize for throwing that out there without qualifying it and having the data to back it up. I've engineered about a half dozen of these machines since making the switch and haven't used a soft start since. And the customer would have complained if the pricing was getting high. So maybe there is something I'm missing and don't have the memory to recall it.

 

[rQx]

And I apologize for throwing that out there without qualifying it and having the data to back it up. I've engineered about a half dozen of these machines since making the switch and haven't used a soft start since. And the customer would have complained if the pricing was getting high. So maybe there is something I'm missing and don't have the memory to recall it.

No need for apologizing, I'm sure you have a very good reason to use the products you use. After all the VFD is a very good (best) and gentle way of starting motors.