What Ssr?

[hockadays]

Hello people,

Just a question on SSRs. I'm ordering a Auber Pid 2362 to control a 3600W element and a Auber Pid 2352 ramp/soak to control a 2400w element and wanting to know what SSRs to buy. Will the 25A ssr be ok or should I be getting the 40A. I have a 15A circuit at home and all work s being done by my sparky but he is away at the moment and I'm ordering in the next few days. ANy ideas??

hockers

 

[fraser_john]

Hello people,

Just a question on SSRs. I'm ordering a Auber Pid 2362 to control a 3600W element and a Auber Pid 2352 ramp/soak to control a 2400w element and wanting to know what SSRs to buy. Will the 25A ssr be ok or should I be getting the 40A. I have a 15A circuit at home and all work s being done by my sparky but he is away at the moment and I'm ordering in the next few days. ANy ideas??

hockers

Formula is P(watts)=V(volts) * I(amps)

So 3600W element draws 15 amps. The 25A SSR would be plenty.

John

 

[newguy]

Heater current = rated power / line voltage. A 25A SSR will do.

 

[Sammus]

Those ratings are assuming the SSR has decent heatsink. I use a 40A just bolted to plastic and it gets quite hot switching a 10A load. Make sure you use a heatsink it if you only get the 25A. May even need one for the 40A, or at least some airflow over it.

 

[fraser_john]

Yes, heatsink is a must, I have 40A one switching a 20A load and it gets quite warm and that's with a large heatsink and the correct compound on it as well!

 

[kirem]

I go for the largest one my budget can afford. I have 40A SSRs on 3.6kW loads and use the front of my control cabinet as the heat sink (with thermal grease and the enamel taken off the door). The door still gets a bit warm around the SSR.

 

[hockadays]

ok so maybe the 40A for the 3.6kw and the 25A for the 2.4kw both with heat sinks..
Does this sound like a good plan

 

[fraser_john]

Like Kirem said, buy two 40A if the price difference is not that great, never know what you might want to do in the future! Otherwise, the 25A would be no issue!

B)

John

 

[schooey]

I have Omron 40A SSR's. The data sheet for them only rates it at 6-8A without a heat sink. I bought my heat sinks from Ocean Controls in Melbourne... here

 

[Sammus]

I just realised my 40A switching one was switching a much smaller load than I though, only a 800W element. That was sealed in a little plastic box with no heatsink though got warm nothing to worry about though. Definately heatsink it for a 15A load, and go the biggest you can.

 

[fraser_john]

I have Omron 40A SSR's. The data sheet for them only rates it at 6-8A without a heat sink. I bought my heat sinks from Ocean Controls in Melbourne... here

Wow, that is low without a heat sink isn't it! I cannot recall what brand mine is, buts its controlling a 20A load using the 40A SSR and the heat sink is reasonably warm to touch, not hot, but close. At a guess, the heat sink is about 6cm by 5cm and finned on either side. It was pretty cheap from memory, so it's good insurance for the price.

I don't have a picture of it on my web site, I guess that's something to add whilst building the new control box. Boy this DIN mount heat sinks would look good in my control box though, nice link schooey!

John

 

[schooey]

That's the one I have in my brew rig panel. It's on a 100x60mm Heatsink with the super duper thermal paste you get from Jaycar. It only gets mildly warmish switching a 3600W element.

 

[fraser_john]

View attachment 26814

That's the one I have in my brew rig panel. It's on a 100x60mm Heatsink with the super duper thermal paste you get from Jaycar. It only gets mildly warmish switching a 3600W element.

Dammit.....that looks sweet! Oh well, what's a few extra bucks spent on my control panel!

John

 

[Thirsty Boy]

Sorry to dredge up an old thread - but Bribie G's cat will bite me if I start a new thread........

Just a question about SSR size - I'm looking on ebay and the cost difference between a 25A and a 60A SSR is on the order of $10. Half the time with a heat sink thrown in.

Is there any reason to not go big on the SSR?? I'll only be pulling 10A resistive through it 90% of the time (200-2400W elements for my RIMS, HLT, Kettle etc), occasionally I might use it to run a fridge (all via PID)

So I understand that I wont "need" a 60A unit... but is there any physical reason to not use a relay that big? I'd rather go over the top and not have to be concerned and also to cater for possible future upgrades.

Also - I understand (perhaps incorrectly) that a zero voltage switch SSR is the appropriate choice for a resistive load - an a random switch on SSR is better for an inductive load... I thought the zero switched one my case because its mainly running heating elements... but that will still be OK for occasional use driving fridge and maybe pump motors wont it??

Thanks

Thirsty

 

[crozdog]

Sorry to dredge up an old thread - but Bribie G's cat will bite me if I start a new thread........

Just a question about SSR size - I'm looking on ebay and the cost difference between a 25A and a 60A SSR is on the order of $10. Half the time with a heat sink thrown in.

Is there any reason to not go big on the SSR?? I'll only be pulling 10A resistive through it 90% of the time (200-2400W elements for my RIMS, HLT, Kettle etc), occasionally I might use it to run a fridge (all via PID)

So I understand that I wont "need" a 60A unit... but is there any physical reason to not use a relay that big? I'd rather go over the top and not have to be concerned and also to cater for possible future upgrades.

Also - I understand (perhaps incorrectly) that a zero voltage switch SSR is the appropriate choice for a resistive load - an a random switch on SSR is better for an inductive load... I thought the zero switched one my case because its mainly running heating elements... but that will still be OK for occasional use driving fridge and maybe pump motors wont it??

Thanks

Thirsty

Hi Thirsty,

No issues with using a higher rated SSR. you just won't be stressing it & will have capacity if you decide to use it for a bigger load in future.

Can't comment on the zero voltage crossing. I can say that I'm using a regular SSR to drive my fridge controller no probs.

Croz

 

[Spartan 117]

Formula is P(watts)=V(volts) * I(amps)

So 3600W element draws 15 amps. The 25A SSR would be plenty.

John

nice way of sorting that out mate, with SSR's the tend to get "stuck" with a rapid increase in power (surges and alike) so you best get the 25A one rather than anything lower even though you only really need about 17A