Another Sealey "soft start" compressor switch failed. Is there an alternative?

[rcx132]

My Sealey 150 L compressor has a soft start system. When the tank gets to 150 psi the pressure switch turns off the motor and then it purges the air out of the pipe between the motor and the tank. This means that when the motor starts again then the motor has a soft start.

The system relies on a special pressure switch that has the mechanism to purge the air hose each time. Sealey charge £70 for this switch, compare to £20 for a generic switch. I use my compressor twice a month, I've had it five years, and I now need to buy third such switch. I haven't looked what's broken yet, maybe it's fixable.

Can anyone think of an alternative to using this switch. Maybe something fancy like a solenoid valve that activates each time the power is cut off to the motor.

 

[the snooper]

All compressors have that feature, it's not soft start, soft start is when the motor starts very slow and builds speed, the valve on the switch is an unloader valve which releases pressure from the delivery pipe, what is it that keeps failing on yours ?

 

[rcx132]

All compressors have that feature, it's not soft start, soft start is when the motor starts very slow and builds speed, the valve on the switch is an unloader valve which releases pressure from the delivery pipe, what is it that keeps failing on yours ?

I can't remember what failed last time, they swapped it under warranty. My workshop is being rebuilt so I can't inspect the one that's just failed.

So you reckon I can find a cheaper generic valve then?

 

[daleyd]

They are about 10 quid on eBay complete with pressure gauge and manifold etc, bought one for mine but didn't need it in the end as it turned out to be a piece of old rawl plug stuck in the mechanism.

 

[the snooper]

There are plenty of cheaper switches out there but it all depends what is failing is it electrical or on the valve side of things if the switch bus burning out there has to be a cause

 

[daleyd]

https://www.ebay.co.uk/itm/371166079286

 

[rcx132]

Awesome, didn't think the generic ones had this feature, very happy not to have to keep giving Sealey £70 each year!

When my workshop is fixed I'll looked at what failed on the last one. It is continuously "unloading" I think.

 

[the snooper]

Awesome, didn't think the generic ones had this feature, very happy not to have to keep giving Sealey £70 each year!

When my workshop is fixed I'll looked at what failed on the last one. It is continuously "unloading" I think.

If it's doing that it's your non return valve at the end of the delivery pipe on the receiver, your switch and valve will be fine, empty all pressure take the valve apart and clean it

 

[daleyd]

Yeah the sealey ones will be exactly the same, just with a horrendous mark up on them!

As snooper said it sounds a bit like the non return valve perhaps rather than the cut out switch/unloader valve - a bit of testing should be able to find out where the problem lies.

 

[WorkshopChris]

Yeah the sealey ones will be exactly the same, just with a horrendous mark up on them!

As snooper said it sounds a bit like the non return valve perhaps rather than the cut out switch/unloader valve - a bit of testing should be able to find out where the problem lies.

Another case of snake oil marketing by manufactures give a technical name to a feature that has been around since the year dot.

 

[rcx132]

Another case of snake oil marketing by manufactures give a technical name to a feature that has been around since the year dot.

I think in their sales bumph they say that the combination of the capacitors fitted to the motor and the unloader are their "soft start" system.

 

[the snooper]

I think in their sales bumph they say that the combination of the capacitors fitted to the motor and the unloader are their "soft start" system.

If there are 2 capacitors fitted to the motor 1 will be for starting and the other a run capacitor

 

[daleyd]

The unloader valve is used in all(or certainly most) compressors, it's not unique to sealey.

Without this the motor would struggle to turn the pump over when starting with a part pressurised tank.

 

[EddyP]

Is there a type of unloader switch that can be operated remotely? From what I remember the unloader on these works as part of the red button and is a manual operation.

I've got my compressor wired up through a contractor so I can remotely start/stop it, it doesn't have an unloader at all, there was never one fitted. It might be better for it to have one.

 

[the snooper]

Is there a type of unloader switch that can be operated remotely? From what I remember the unloader on these works as part of the red button and is a manual operation.

I've got my compressor wired up through a contractor so I can remotely start/stop it, it doesn't have an unloader at all, there was never one fitted. It might be better for it to have one.

the unloader is automatic the pressure switch operates it but so does the red button as you say

 

[ukracer]

the unloader is automatic the pressure switch operates it but so does the red button as you say

Does that mean you could wire a remote switch in parallel to do the job?

 

[the snooper]

you could only use the remote switch safely to switch off if you switched off after the unloader valve had released the pressure

 

[ukracer]

you could only use the remote switch safely to switch off if you switched off after the unloader valve had released the pressure

I was thinking.more of triggering the unloader.....

 

[the snooper]

I was thinking.more of triggering the unloader.....

the unloader is operated mechanically on the compressor by the pressure switch so in order to do it remotly you would need a solenoid valve that vents when not powered so when you switch off the valve empties the delivery pipe then on powering up the power would close the valve

 

[ukracer]

the unloader is operated mechanically on the compressor by the pressure switch so in order to do it remotly you would need a solenoid valve that vents when not powered so when you switch off the valve empties the delivery pipe then on powering up the power would close the valve

Cheers mate....