Silicone bed 12V directly to PSU???

Wiring relay and sillicone heatbed (i have g.cartier 12V-50A automotive relay, and 12V 280W sillicone heater)


You have 4 wires that needs to be hooked up to relay

Plus from relay (number 1 on relay) goes to D8+ on ramps, second wire (number 2 on relay) from relay goes to D8- , third wire from relay (number 3 on relay) goes to + on your PSU, wire number 4 from relay (number 5 on relay) goes to sillicone bed, the last wire from heatbed goes to - on PSU

DONT WIRE - AND + WRONG WAY FROM RELAY TO RAMPS CAUSE THERE IS CHANCE TO FRIED IT.

You need to know wiring schematic on relay

Edited 1 time(s). Last edit at 02/18/2016 03:53PM by Beer4Brew.

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smoothol
12v means high current which = fatality


lol


so should i do the same set up as you with an automotive relay?
please could you share the component and wiring details

You can use 12V heater with relay without worries, if You have good relay to be sure 50A

Edited 1 time(s). Last edit at 02/18/2016 03:51PM by Beer4Brew.

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smoothol

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dc42

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smoothol

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dc42
For a heated bed of that size, you should use one of the following:

1. AC mains voltage bed heater, driven using a DC-AC SST. Only do this if you are knowledgeable about and comfortable with doing mains voltage wiring.

2. A 24V bed heater (in which case you may as well run the entire printer on 24V, assuming you use 24V-capable electronics). The bed heater will draw 13.75A. Some electronics can handle this current directly (e.g. the Duet 0.8.5 should be OK at this current). Otherwise, use a good (low drop) DC-DC SSR or the Power Expander from reprap.me

could I not use 12v heatbed and a SSR with a higher amp resistance for instance 50A RRS?

Bad idea. Dealing with such high currents is not nice, and keeping the resistance low enough is not easy.

ahhh okay i may switch to 24v then.... so to sum it all up theres no way of controlling the temperature of the heatbed from the MKS board??

That depends on whether the MKS board you want to use is 24V capable and its heated bed circuit can switch 14A. I suggest you check it's specifications.

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

hello again,

i have set up my 240V ac mains to the heatbed and SSR... then connected the DC + - to the MKS base heatbed output + -


the problem is that the relay isnt switching? any ideas?
or could it be something in the firmware?

cheers
O.T