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SSR testing

Craig, what's the size of the 500A SSR heatsink? As you see thermals dictate how much current you can push through them. I'm planning on building my own SSR. I had to guess on the size of the heatsink. Got this on order:
2 inch heatsink

STP80PF55 mosfets have a on resistance of 18 mohm. I'll see if 4 or 5 mosfets fit on the heatsink. That drops resistance down to 4.5 to 3.6 mohm. That's still a lot more than 1.43 mohm measured on the 500A SSR. But I just want to switch 20A max.

Curious on the size of your heatsink.
 
Cal said:
Craig, what's the size of the 500A SSR heatsink? As you see thermals dictate how much current you can push through them. I'm planning on building my own SSR. I had to guess on the size of the heatsink. Got this on order:
2 inch heatsink

STP80PF55 mosfets have a on resistance of 18 mohm. I'll see if 4 or 5 mosfets fit on the heatsink. That drops resistance down to 4.5 to 3.6 mohm. That's still a lot more than 1.43 mohm measured on the 500A SSR. But I just want to switch 20A max.

Curious on the size of your heatsink.
Click to expand...
The heatsink is about 2.5 x 4 x 4 inches.
 
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When I worked for a building control company, we used a LOT of the RIB relays. The coil only draws 15 ma at 12V. The one we used the most was the RIBU1C. I think that one is only 10A contacts, but not sure if I remembered that right. It would probably work well for switching an inverter.
The Pro's are that it has a modular case and is easy to mount. It has an LED indicator. It is inexpensive and has a wide range of coil voltages.
The con's is that there will be unused wires that will have to be clipped and capped with a wire nut or similar.

We used hundreds of thousands of these over time and a failure was VERY rare.
 
Capt Bill said:
So basically this is a way to have either charge or discharge side BMS triggers signal turn off / disconnect the whole battery connection via "one relay". The disadvantage I notice, that is not a total disadvantgage; is that if your BMS got trigger for low cell voltage, if charger input to battery was left intact, you could potentially have situation remedied automatically. On the other side of that idea: With everything turned off; that will likely require your attention get it back on? Do you agree? Sometimes, maybe that could be better ? I would prefer auto protection. ... I guess if it was a heat or max amp fault trigger, the BMS could automatically recover operation, but not for a low voltage trigger.
Click to expand...

If you have separate charge/discharge paths then you should use the two contactor option that I described. If you have a common port setup then two contactors won't help. There is nothing about the contactor/module idea that effects system operation. That is all built within the system architecture (common charge/discharge or not) and BMS settings.
 
Bob B said:
When I worked for a building control company, we used a LOT of the RIB relays. The coil only draws 15 ma at 12V. The one we used the most was the RIBU1C. I think that one is only 10A contacts, but not sure if I remembered that right. It would probably work well for switching an inverter.
The Pro's are that it has a modular case and is easy to mount. It has an LED indicator. It is inexpensive and has a wide range of coil voltages.
The con's is that there will be unused wires that will have to be clipped and capped with a wire nut or similar.

We used hundreds of thousands of these over time and a failure was VERY rare.
Click to expand...
 
Craig said:
Yes I think we need to target switching whatever area that moves the least amount of amps.
Click to expand...
Re: Targeting Solar Panels Input for charge side relay control from BMS; I found this up to 150 VDC / 120 Amp SSR on Mouser :
I would need an SSR that could handle 30 Amps on that route, so thinking one rated for 60 -100 amp might be good idea. IMO: The problem with the Mouser supplied SSR is the $227 price kind of kills that one (for me). WONDERING what the Alibaba SSR options will be for handling 150 vdc / and about 60 - 100 amps ?


My brief search at mouser did not reveal any good looking prices for a SSR I might consider. I noticed spec saying Maximum On-State Voltage Drop @ Rated 120 amp Current [V DC] was .53 volts which also seem like a negative factor (but might not be at 20- 30 amps). ... I am open to finding a coil relay too; for switching Solar Input to OFF via a BMS trigger. ... If excessive coil draw was a concern; I would also consider a NC (normally closed) relay and figure out some in between piece that would take BMS releasing of dc v and convert that into current to open a NC relay ... All kind of options.
 
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Capt Bill said:
Re: Targeting Solar Panels Input for charge side relay control from BMS; I found this up to 150 VDC / 120 Amp SSR on Mouser :
I would need an SSR that could handle 30 Amps on that route, so thinking one rated for 60 -100 amp might be good idea. IMO: The problem with the Mouser supplied SSR is the $227 price kind of kills that one (for me). WONDERING what the Alibaba SSR options will be for handling 150 vdc / and about 60 - 100 amps ?


My brief search at mouser did not reveal any good looking prices for a SSR I might consider. I noticed spec saying Maximum On-State Voltage Drop @ Rated 120 amp Current [V DC] was .53 volts which also seem like a negative factor. ... I am open to finding a coil relay too switching Solar Input off via a BMS trigger. ... and if coil draw was of any concern; I would also consider a NC (normally closed) relay and figure out some in between piece that would take BMS releasing of dc v of relay trigger/ and turn that into current to open a NC relay ... All kind of options.
Click to expand...
I have my original 500 amp SSR I will test with my panels I think I can configure for 30 Amps or so. This relay would be less than $100 shipped.
I do not know but im hoping the nature of MPPT might be easier on the relay than a continuous discharge from the inverter as well. I will also test a smaller 80 Amp one if I can find it.
 
Craig said:
I do not know but im hoping the nature of MPPT might be easier on the relay than a continuous discharge from the inverter as well. I will also test a smaller 80 Amp one if I can find it.
Click to expand...
I found this on eBay, from China: Look like inexpensive candidate for SSR on Solar Panel input side: listed as:
High Quality 100A Solid State Relay SSR DC-DC 100A 3V-32V DC 5V-220V DC for less than $30

www.ebay.com

High Quality 100A Solid State Relay SSR DC-DC 100A 3V-32V DC 5V-220V DC | eBay

Load Current: 100A. 1 x Solid State Relay. Insulation Resistance : 500M ohm/500VDC.
www.ebay.com

or similar on Aliexpress at less that 1/2 above price. I have no idea of durability or voltage drop through unit. Did recently read that some SRRs are sensitive to polarity of DC connect through unit; and reversed (from specified) current flows on some SSR can damage em. On link below: I would choose the 100 Amp version, plus that heat sink. Might order a set next; Curious to test .

www.aliexpress.com

US $4.81 30% OFF|CG SSR 60DA 80DA 100DA Relay Single Phase DC Control AC 24 480VAC 3 32VDC Heat Sink 60A 80A 100A DA Solid State Relay|Relays| - AliExpress

Smarter Shopping, Better Living! Aliexpress.com
www.aliexpress.com www.aliexpress.com
 
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Pacer said:
I am right on with you here. BMS will be a total backup to the SCC, and I’m cool with a single disconnect point for either scenario.

Can you elaborate on what you mean by the 24/12 DC converter part? You are going to control your 12v accessories the same way?
Click to expand...
Since I'm building a 24V battery bank, I'm using the Victron 24/12V DC/DC 70A convertor to provide 12V power for my RV DC system.
 
Capt Bill said:
I found this on eBay, from China: Look like inexpensive candidate for SSR on Solar Panel input side: listed as:
High Quality 100A Solid State Relay SSR DC-DC 100A 3V-32V DC 5V-220V DC for less than $30

www.ebay.com

High Quality 100A Solid State Relay SSR DC-DC 100A 3V-32V DC 5V-220V DC | eBay

Load Current: 100A. 1 x Solid State Relay. Insulation Resistance : 500M ohm/500VDC.
www.ebay.com

or similar on Aliexpress at less that 1/2 above price. I have no idea of durability or voltage drop through unit. Did recently read that some SRRs are sensitive to polarity of DC connect through unit; and reversed (from specified) current flows on some SSR can damage em. On link below: I would choose the 100 Amp version, plus that heat sink. Might order a set next; Curious to test .

www.aliexpress.com

US $4.81 30% OFF|CG SSR 60DA 80DA 100DA Relay Single Phase DC Control AC 24 480VAC 3 32VDC Heat Sink 60A 80A 100A DA Solid State Relay|Relays| - AliExpress

Smarter Shopping, Better Living! Aliexpress.com
www.aliexpress.com www.aliexpress.com
Click to expand...
OPPS .. I see I posted a wrong link for a DC - AC SSR. I meant to post link to a DC - DC SSR rated for 100 A or 120 A ... & up to 220 vdc. I ended up ordering one via eBay that will take awhile shipping from China ... Curious to Test, and it will maybe give me a usable option for cutting off Solar Volt * Amps (for either 70vdc x 30 amps IN or 115vdc x 20 amps IN to All In One) when a BMS low cell voltage or some other charge side trigger turns the SSR to OFF. I only spent $ 22. Might be a waist of time, but could possibly work ok, since it over rated for what I need.
 
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Simple Thermal Disc Control for SSR + Mechanical Relay in Parallel
Interesting option to Solo 500 Amp dc-dc SSR:

I got this idea today while motorcycling today, for dealing with the extra watts used, heat produced, and slight volt loss at SSR relay contacts; when running Higher Amp Currents through a SSR (Solid State Relay). All those costs are a non issue at low amp currents. Here's a Remedy I read about recently @electronics.stackexchange.com: Wire a mechanical / NO normally open Relay in parralell with the SSR (w matched amp ratings); This Control Idea is the new one that bubbled today: Trip that mechanic relay via a thermal disc placed on the the heat sink side of the SSR (& might not even need a heat sink) ... When the mechanical relay is tripped by heat on the thermal disc switch; that mechanical relay would then be the one transferring the big amps (via the less resistance route as compared to the SSR at high amps) without heating up like a SSR: Other advantages: The higher coil wattage draw of mechanic relay would only cycle during periods of higher amps draws (way less than 24 hrs/ 7 days per week for solo mechanical relay). Plus the mechanic relay lifespand grows noticably w less electrical arcs. A lower cost, lower watt rated SSR might work dependably with this set up. The new idea is to simply use a Thermal Disc to Control the second parrallel mechanical relay. Easy, economical, dependable, and automatic. Sounds just like what most forum members want and value. I'd pick a lower trip temp /from one of those thermal disc suppliers for attic fans, and/or for gas heater fans, etc.

The parrallel SSR with mechanical relay idea has been out there for a long time! I wonder what kind of control have been used in past for that? The simple $10 or $15 thermal disc control might be a new idea? Craig, Steve, ... I am bouncing off the feedback of your past SSR testing . If this idea proves productive, I request you remember ... (unless you heard of idea before) This Thermal Disc Control Idea Bubbled up in Capt Bill while riding his motorcycle on Mother's Day (maybe like in the Hundredth Monkey Story
 
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Capt Bill said:
Simple Thermal Disc Control for SSR + Mechanical Relay in Parallel
Interesting option to Solo 500 Amp dc-dc SSR:

I got this idea today while motorcycling today, for dealing with the extra watts used, heat produced, and slight volt loss at SSR relay contacts; when running Higher Amp Currents through a SSR (Solid State Relay). All those costs are a non issue at low amp currents. Here's a Remedy I read about recently @electronics.stackexchange.com: Wire a mechanical / NO normally open Relay in parralell with the SSR (w matched amp ratings); This Control Idea is the new one that bubbled today: Trip that mechanic relay via a thermal disc placed on the the heat sink side of the SSR (& might not even need a heat sink) ... When the mechanical relay is tripped by heat on the thermal disc switch; that mechanical relay would then be the one transferring the big amps (the less resistance route compared to the SSR at high amps) without heating up like a SSR: Other advantages: The higher coil wattage draw of mechanic relay would only cycle during periods of higher amps draws (way less than 24 hrs/ 7 days per week for solo mechanical relay). Plus the mechanic relay lifespand grows to infinity w less electrical arcs. I bet a low watt rated on SSR could work with this set up. The new idea is to simply use a Thermal Disc to Control the second parrallel mechanical relay. IMO: Easy, economical, dependable, and automatic. Sounds just like what most forum members want and value. I'd pick a lower trip temp /from one of those thermal disc suppliers for attic fans, and/or for gas heater fans, etc.

The parrallel SSR with mechanical relay idea has been out there for a long time! I wonder what kind of control have been used in past for that? The simple $10 or $15 thermal disc control might be a new idea? Craig, Steve, ... I am bouncing off the feedback of your past SSR testing . If this idea proves productive, I request you remember ... (unless you heard of idea before) This Thermal Disc Control Idea Bubbled up in Capt Bill while riding his motorcycle on Mother's Day (maybe like in the Hundredth Monkey Story
Click to expand...
I like the idea and I think it may be similar to something Chargery could be working on. It would also be possible to kick big relay on at high amps as well so say after 10 seconds at X amps the big relay kicks on. Same concept as thermal.
 
Will Prowse: I think you might like this test and demonstrate idea for your YouTube channel. ???
Simple Thermal Disc Control for SSR + Mechanical Relay in Parallel ... as option to solo SSR

Re: Craig and/or Steve S's Testing of SSRs for BMS control of high amp 24 vdc or 48vdc Battery current:
... Copying Craig's Test Results from SSR testing thread:
Tested 500 Amp SSR with 160 Amps at 24 volts / 15 minutes / 140F (w Craig's: I do not find this acceptable)
Tested 200 Amp SSR with 60 Amps at 24 volts / got to 160 Degrees F (a Craig's IMO: not at all sustainable)

*********
Are there any reasonably priced Hybrid SSR - Mechanical Relay with a 48 Vdc (or more) x 500 Amp (or more) Ratings ???
available on the market ??? I am currently thinking if there was, you guys would already be talking about them, plus using them!

How about demonstrating this idea of a Hybrid SSR- Mechanical Relay with Simple Thermal Disc Control:
with Snap Disc Thermostat Switch - Circuit On At 100°F and Off At 85°F (I have used these for ventilation fans, & IMO: quite durable)

Senasys Snap Disc Thermostat Switch - Circuit On At 100°F and Off At 85°F - Large Flange, Part Number 2511F002-351 - Temperature Sensors - Amazon.com

Senasys Snap Disc Thermostat Switch - Circuit On At 100°F and Off At 85°F - Large Flange, Part Number 2511F002-351 - Temperature Sensors - Amazon.com
www.amazon.com

Re: Thermal Disc options: I am sure we could find one that triggers ON @ a lower temp and/or is adjustable too.

My thoughts are: Take the 200 Amp or 500 Amp dc-dc SSR that is kept ON via a continuous 12v trigger from BMS (until a fault removes relay volts) ... then wire a best looking deal kind of 500 Amp dc volt rated Mechanical Relay in Parallel to SSR (matching current directions ? & wire same 12v BMS to relay trip circuit to the Mechanical Relay coil through a Thermal Disc solidly placed or thermal glued to heat sink side of SSR.

I am confident this could make an inspiring Will Prowse YouTube lesson. If the suppliers are working on this now, it might speed em up to see how economically a DIY can put this together. If you have not yet seen this idea of using a simple thermal disc for relay control, I request you remember: That Idea bubbled up in Capt Bill while Motorcycling on Mother's Day (after learning more from Will Prowse and the DIY Solar Forum/ on his 70th orbit around sun while on his learning more all the time progam !
 
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Hope I am not posting too much ... got a bug in me to study options, and wrote this:

On the other side of solo SSR vs solo Mechanical Relay considerations; I found this on eBay:

TE Connectivity Kilovac EV200AAANA Contactor 500A, 12~24VDC Coil. USA Shipper.
Open Box deal $80 ...
www.ebay.com

TE Connectivity Kilovac EV200AAANA Contactor 500A, 12~24VDC Coil. USA Shipper. | eBay

Check out the datasheet for specifics. Built-in coil economizer – only 1.7W hold power @ 12VDC and it limits back EMF to 0V.
www.ebay.com

I noticed the description says: Designed to be the smallest,lightest weight, lowest cost sealed contactor in the industry with its current rating (500+A carry, 2000Ainterrupt at 320VDC). * Built-in coil economizer - only 1.7W hold power @ 12VDC and it limits back EMF to 0V.
stocked from a liquidation. Some Mexico manufacture, some China, all are the same spec and part number.

Wow to TE Connectivity Kilovac's ... only 1.7W hold power @ 12VDC spec. ( sounds very good if confirmed
vs Info. from Criag's testing of 200 Amp SSR with 60 Amps at 24 volts / current draw from the control side at 12V was .1 amp so 1.2 watts
(Not much less than 1.7 Watt coil hold power of the TE-Connectivity-Kilovac. Plus the SSR had a Voltage drop at 60 amps across relay of .9V (Craig: seems way high to me but i do not know what to expect) battery was at 30.0v load side of SSR 29.1v

This ebay find does have me wondering about SSRs for high amp current applications. I ordered a few SSR to test out and likely use in lower amp application like making BMS cut off option at Solar DC volts In to all in one unit/ cut off by certain BMS battery fault trigger).

It Would Be nice to see a list of different SSR and mechanical relays next to the watts needed for ON switch, ... that usually stay triggered 24/7 until released by BMS registering a battery fault. Maybe solo mechanic relay is OK idea when one finds a dependable one with a Built-in coil economizer (wonder how economizer coil works, and what range of watt draws are out there ???

I see SSR testing looking for: Which SSRs use the least amount of dc trigger watts/ and can handle the high dc amps, with the least amount of heat and voltage drop ! Will Prowse: I still think a YouTube clip demonstrating a simple thermal disc control of a 2nd mechanic relay trigger after SRR ... would be good idea, including for sending a message to manufacturing process: The DIY Solar Community wants dependable high amp relays with the lowest possible control side current draws, and the least amount of voltage drops; for our solar systems. Plus: We can make our own until we see better choices, at good deal prices (or something like that !!!
 
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I know some have gotten the Kilovacs but I have not heard their results. Honestly I was hoping for a cheaper solution. The huge 500Amp SSR even if they worked were still way more costly then I hopped. My initial texting of AC SSR has gone well but I only ran about 1500 watts through it. For 30 minutes. Temp increase was only 5F above ambient. Hope to do a 2500 watt test tonight. But that is the largest inverter I have at home.

So with this method 1 200Amp DC DC SSR fir DC loads and 1 100 amp DcAc SSR for inverter.
 
On the TE Relays. They are Polarised. Per the spec sheet, with reverse polarity (incoming) the relay derates 50%
The Listing you posted is expired as well.


I've given up on LieChuanTec and Allen, they have gone Non-Communicative. 7 days with no response.
Also have pretty much given up on Dongya and their DH200 series... I don't get but they also went Non-Communicative, 8 days now...
It is ironic but maybe a good thing. Neither of what I got from these two companies are of use to me in a Common Port configuration. Ironic as apparently the Dongya DH200AAANH (non-polarised energy saver) would have been the ticket.

I'm taking a different route and no more furtling with this as it's holding my installation up. I'm looking at the TE / Kilovac & Gigavac types and others.
 
I still think there may be a durable inexpensive way to use the thermal disc control idea on the SSR + Mechanical Relay in Parallel idea; while possibly keeping the expense down by depending on the parrallel power of two relay circuits; like maybe use half the amp rated relays to get full max amp needed.

I will likely test a thermal disc on a SSR to second relay as back up way to protect from overheating and inexpensive SSR. I ordered some inexpensive options to play with. I also am considering the lesser 50 amp type circuits to put controls on in my future, like my solar panel lines IN, and possibly 120 vac out line. I am also looking at the four wires of two contrasting circuits going to the one OFF/ON Switch in my green LV2424 All In One; & wondering if one set goes to the inverter, and other to MPPT battery charger ??? for possibly setting up BMS control via two 5 amp rated SRRs connected to charge and discharge control sides of Chargery (but still got questions, and would not want to kill my warranty/ & still waiting for battery delivery. Happy Trails ...
 
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Capt Bill said:
I still thin there may be a durable inexpensive way to use the thermal disc control idea on the SSR + Mechanical Relay in Parallel idea; while possibly keeping the expense down by depending on the parrallel power of two relay circuits; maybe use half the amp rated relays to get full max amp needed.

I will likely test a thermal disc on a SSR to second relay as back up way to protect from overheating and inexpensive SSR. I ordered some inexpensive options to play with. I also am considering the lesser 50 amp type circuits to put controls on in my future, like my solar panel lines IN, and possibly 120 vac out line. I am also looking at the four wires of two contrasting circuits going to the one OFF/ON Switch in my green LV2424 All In One; & wondering if one set goes to the inverter, and other to MPPT battery charger ??? for possibly setting up BMS control via two 5 amp rated SRRs connected to charge and discharge control sides of Chargery (but still got questions, and would not want to kill my warranty/ & still waiting for battery delivery. Happy Trails ...
Click to expand...
I like the thermal Idea I just think the temperature of the ones listed won't quite work. It probably would be fine in the coast but in Arizona it would always be on since ambient temperature is usually above 85F at least in the summer
 
Craig said:
https://www.amazon.com/Termostato-1...&keywords=dc+thermostat&qid=1589252726&sr=8-4

@Capt Bill take a look at the above I think it will work better as a thermostat to control the big relays.
Click to expand...
My First Question was: What is idle consumption; ... when wanting minimum 24/7 relay coil and SSR trigger consumption. Found: Power Consumption: 3W (might be less when no relay is triggered?) My Thoughts then put that along side a solo relay option; the Kilovac 500 amp Relay with coil energizer feature get specs for 0.13 amp @ 12v for 1.7 Watts on coil. IMO: That Digital Temperature Control looks like something to dial in the optimal temps for switching on a second Parallel mechanical relay, to then find a thermal disc to match those findings. While 3 watts is almost nothing / the thermal disc is zero energy consumption, plus also (I believe with proper supply) durable. ... Appreciate knowing about a Temperature Control for only $15. Looks like something DIYs might especially consider (with the fan and mini heater options shown on same page), for controlling temperature in a battery box. and/or a green house. ... I put one on my Amazon cart as way to easily go find and order later ;+)
 
Re: Selection of Thermal Disc: I think that earlier one I pitched for on at 100 F/ off at 85F for cut out is too low, as I would want set up to turn off second parallel mechanical relay when amps through SSR reduce to minimal heat. An 85 F cut off would be too low some seasons or locations, ... so I am bumping up a notch to test / canceled a previous disc order to replace with better choice for a test at later date (though I am not personally aiming for a 500 Amp BMS cut off switch) Decided upping temp range of thermal disc for cut in temp 120 F, then cut off 110 F (or an adjustable option): is better choice that I think could work in most situations. ...for just wanting 2nd relay cut in when running higher amps.

Emerson 3F01-120 Snap Disc Fan Control - Ceiling Fan Accessories - Amazon.com

Emerson 3F01-120 Snap Disc Fan Control - Ceiling Fan Accessories - Amazon.com
www.amazon.com
or play with adjustments

Amazon.com: Emerson 3F05-1 Adjustable Snap Disc Fan Control : Home & Kitchen

Amazon.com: Emerson 3F05-1 Adjustable Snap Disc Fan Control : Home & Kitchen
www.amazon.com
 
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