Tandem compressor control box.

[Domeo_jones]

Hi all did a post a while ago about thought of a tandem compressor using 3 phase motors (as they are cheap) and a duel vfd to drive them.
Anyway, now a super cheap yet dirty and possibly need a bit of a service tandem compessor has popped up on my radar..
Unfortunately the control box is being used on another compressor so basically whst is the control box called and where can I buy/make one. .
Thank you all for your knowledge and just general keeping everyone's head up in these difficult times.

 

[brightspark]

all is you need is is a couple of contactors 2 switches and a timer to delay the second one coming on at same time .you only need about 6 second delay on start up and wire the relay contactor coils through the pressure switch and put em in a plastic enclosure should be able to knock one up for less than 45 quid

 

[Domeo_jones]

all is you need is is a couple of contactors 2 switches and a timer to delay the second one coming on at same time .you only need about 6 second delay on start up and wire the relay contactor coils through the pressure switch and put em in a plastic enclosure should be able to knock one up for less than 45 quid

You are a clever fella...
Where can I get the leccy stuff you reckon... I'm a chippy so I'm guessing screwfix won't help me.
I bloody love this place.

 

[brightspark]

ebay or anywhere for the contactors at the cheapest price same as the timer are you going to run on single phase with 3hp motors

 

[eil]

If you are using two VFD`s then you wont need contactors, and you could dial in a delay on one inverter.

 

[brightspark]

If you are using two VFD`s then you wont need contactors, and you could dial in a delay on one inverter.

he said another tandem compressor has turned up so he may get that . presumably single phase but he hasnt said .tandems are normaly single

 

[Domeo_jones]

he said another tandem compressor has turned up so he may get that . presumably single phase but he hasnt said .tandems are normaly single

Yeh just single phase.... so no need for the old vfds just yet... got to clear some extra room for the bloody thing now it looks massive.
Right old to the bay. Thanks... but I may need to ask some more questions.. obviously.

If you are using two VFD`s then you wont need contactors, and you could dial in a delay on one inverter.

 

[Agroshield]

All is you need is is a couple of contactors, 2 switches and a timer to delay the second one coming on at same time.

And once a year, swap over the connections so that the first to start becomes the second to start. This way, the wear on the motors is more equal.

 

[Domeo_jones]

And once a year, swap over the connections so that the first to start becomes the second to start. This way, the wear on the motors is more equal.

Okay so... I'm holding my hands up... I have absolutely no idea of what I'm doing..
There seems to be loads of different types of contractors and then I searched for s contactor timer and it came up with things to grow plant a with... hydroponics or something.. lol.
Just had another look at it and I thought there was chewing gum stick on the capacitors but I unscrewed the clip and found this...
Is this a bad sign?
Also can I bypass the pressure switch and just connect a plug on the wire from the motors to double check they work?
Thanks again... see pic.

 

[500e]

Replace it not good, think "Aliens"

 

[Domeo_jones]

Replace it not good, think "Aliens"

Haha.... it didn't look to clever, can I just whip the one of the other motor and bang a plug on it... just at to check obviously..

 

[brightspark]

you can run each motor of a lead to a plug and run them to try. swap caps before you buy one to test.. it may run on 13 amp conected to the pump without popping the fuse load wise

 

[brightspark]

a couple of these would do it or shop round for cheaper 20 amp 3 or 4 pole will; do it Hylec DEC 3-Pole Contactor Unit 5.5kW | Industrial Contactors | Screwfix.com

 

[Domeo_jones]

you can run each motor of a lead to a plug and run them to try. swap caps before you buy one to test.. it may run on 13 amp conected to the pump without popping the fuse load wise

Brilliant... on that right now... as I'm doing a shopping list of a cap, I couldn't get you to recommend those other bits and pieces for ge box too could I?
Contacts and timer contacts?? Really want to get this bad boy running.

 

[Domeo_jones]

a couple of these would do it or shop round for cheaper 20 amp 3 or 4 pole will; do it Hylec DEC 3-Pole Contactor Unit 5.5kW | Industrial Contactors | Screwfix.com

Beat me to it... how about the timer thing... at 6 secs yeh...
I been reading about start caps and run caps... do I need both types...?

 

[brightspark]

heres a delay timer Brodersen RS 260-498 DPDT TRUE OFF DELAY TIMER 1-30 SEC 240AC | eBay but have a look round elswhere this wass 1st hit hmm heres one cheaper Delay On Make Timer Relay | eBay

 

[Domeo_jones]

So it just turns and then trips the breaker in the garage... so it's kind of good news. Think I need one of those different curves rcds.
Any recommendations??
Bloody thing.. lol
Just to add I'm only running one motor/pump ....

 

[brightspark]

it will take a 16 amp b type out on start up. try it in the ringmain in the house if it has a 13 amp plug fitted then see what happens a- c type 20 would be best if ok

 

[Domeo_jones]

it will take a 16 amp b type out on start up. try it in the ringmain in the house if it has a 13 amp plug fitted then see what happens a- c type 20 would be best if ok

I'll have to get a bigger rcd... no way of plugging it in the house , id need a bit of cable at least 4m to try it on the house lower ring .
I'll order one of those other breakers and try it... this shopping list is getting big...
I'm guessing I'm going to need a 32amp supply running to the garage if I ever want to fire both up lol... but... hey ho.
I just remembered I have about 4 m of 2.5mm cable so I'll try n knock up a extension. Fingers crossed

 

[Domeo_jones]

it will take a 16 amp b type out on start up. try it in the ringmain in the house if it has a 13 amp plug fitted then see what happens a- c type 20 would be best if ok

Fired up one pump lovely I flicked it off after 30 secs as I was worried about the noise but then thought stuff it so tried again and it popped the fuse in the plug... no biggie. so I'm pretty happy with that...
Need to swap caps now and invest in those better rcds for the garage.
And then build one of those boxes but I'm thinking attemptting to run both even with a delay might be pushing it... but if you don't try you won't find out.