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ccr1072 and 48v dc power

Posted: Wed Mar 09, 2016 8:54 am
by popcorrin
I'm wondering what the best way to power the new ccr1072 in a dc environment. Looking at the board it doesn't look to be as easy as connecting a molex connector from a dc power source directly to the board. Looks like their is some extra circuitry between the board and the power supplies.

I would like to avoid an inverter but it's looking like it might be the only option at this point.
Would be nice if mikrotik designed some dc power supplies for this beast.

Re: ccr1072 and 48v dc power

Posted: Wed Mar 09, 2016 9:24 am
by janisk
it is possible to find DC-DC PSU (converter?) and replace the currently used AC-DC PSU with that as CCR1072 will not work from 48V DC drirectly.

Re: ccr1072 and 48v dc power

Posted: Wed Mar 09, 2016 9:38 am
by nz_monkey
it is possible to find DC-DC PSU (converter?) and replace the currently used AC-DC PSU with that as CCR1072 will not work from 48V DC drirectly.
It would be nice if Mikrotik made a 48V DC PSU for the CCR1072.

Re: ccr1072 and 48v dc power

Posted: Wed Mar 09, 2016 10:50 am
by doneware
it is possible to find DC-DC PSU (converter?) and replace the currently used AC-DC PSU with that as CCR1072 will not work from 48V DC drirectly.
i am actually working on that. if i just could get 1-2 emtpy ps trays... don't want to scrap my own.

Re: ccr1072 and 48v dc power

Posted: Wed Mar 09, 2016 8:58 pm
by popcorrin
it is possible to find DC-DC PSU (converter?) and replace the currently used AC-DC PSU with that as CCR1072 will not work from 48V DC drirectly.

I have a dc-dc converter? Does the board take only 12v? Also, how would you connect it to the board. Looks like the power supply and the board are doing more than transferring just power. I assumed the extra wires had something to do with failover. Would there be a way to keep the failover intact?

Re: ccr1072 and 48v dc power

Posted: Wed Jun 08, 2016 6:30 pm
by abernier
I think it is a very interesting topic.

The power at most of telco locations is 48V. It is not logical that Mikrotik doesn't have solutions for that.

Has anyone tried any DC-DC converter?
What model of 48v to 24v build-in converter have you used?


Thanks all

Re: ccr1072 and 48v dc power

Posted: Wed Jun 08, 2016 7:02 pm
by SystemErrorMessage
This is surprising, I thought CCRs had 12V to 48V DC input allowance. I see conflicts everywhere, some of mikrotik's own pages say 12V-48V, the datasheet says 18V-36V. The PSU for mine failed because the voltage dropped from 24V to below 12V after a few minutes of power on. While the PSU was providing 12V (as seen in system health) my CCR1036 was still working fine. When it dipped below 12V it went into a reboot loop. Now im trying to find the compatible component to replace to get it working.

The main problem that caused failure was that the inside of the CCR was running very hot (close to 50C reported by non CPU thermometer) for a long while. The CPU wasnt having any issues nor was it even close to overheating as it was all well below 70C the focused cooling of the CPU means all other components arent adequately cooled. There is no vent at the back for basic convection to happen, no heatsink on some PSU components, no extra fan to help cooling the inside of the case.

Since you need 24V and you have 48V input it should not be difficult for a DC-DC converter.

Re: ccr1072 and 48v dc power

Posted: Wed Jun 15, 2016 1:16 pm
by ofca
We are using pretty much every mikrotik device on +48VDC (+54VDC to be exact) for years now. Just use any DC-DC transformer that fits inside that outputs 24V from 27-60V input and be done with it. DC3HV is one of such, http://ambm.pl/index.php/step-down.html - it would be nice if CCRs and rest supported this, but that's on a long list of things that would be nice, but aren't happening. Like 24 SFP CCRs/CRSs ;)

Re: ccr1072 and 48v dc power

Posted: Fri Jun 17, 2016 6:05 am
by SystemErrorMessage
I managed to fix my CCR, support informed me of what voltages are supported. Although i am using 24V you can use 13-30V for the CCR and it will still work. When the initial PSU was failing and was running at 12V the CCR was still working before the voltage dropped even more and the CCR went into a boot loop.

In order to improve thermals and longevity i have my PSU on the outside for better cooling, by doing this the temperature ambient temperature in the CCR dropped by 8C. The CCR1036 uses 5A PSU so make sure the replacement has 5A. I will post a guide on replacing it later, any PSU that outputs 24V and 5A DC will work. Some soldering and wiring work will be needed and i suggest you use a glue gun and tape to cover any exposed wiring as you will have to add wires to get it long enough for the PSU to be outside.

Re: ccr1072 and 48v dc power

Posted: Fri Jun 17, 2016 7:48 am
by nz_monkey
 The CCR1036 uses 5A PSU so make sure the replacement has 5A. I will post a guide on replacing it later, any PSU that outputs 24V and 5A DC will work. 
The CCR1036 actually uses a 24V @ 4A Power Supply, it is Mikrotik part code WT2400400R2

Re: ccr1072 and 48v dc power

Posted: Fri Jun 17, 2016 9:01 am
by SystemErrorMessage
You're right, thanks for correcting me. Still it is much better to use the PSU outside for temperature reasons. CPU cooling for the CCR is good but very poor case cooling.

Re: ccr1072 and 48v dc power

Posted: Fri Jun 17, 2016 1:22 pm
by nz_monkey
I agree.  The cooling design in the CCR 1036 and 1016 is not perfect :(

There is a single front to back shroud over the CPU. This means the processor is cooled excellently!
However everything else (RAM, Voltage Regulators, PSU, SFP's) relies on passive cooling in to aan almost closed cavity.

A simple low cost design solution would be to punch a grill into the alloy back or sides of the CCR to let the warm air out. .  
e.g.
Image

I will add that the cooling design on the CCR1072 is much improved over the earlier CCR models :)

Re: ccr1072 and 48v dc power

Posted: Fri Sep 02, 2016 6:58 am
by popcorrin
Curious if there is a dc power option for the ccr1072 or how we would hook up dc power directly to the board. Also, what voltages would the ccr1072 accept?

Re: ccr1072 and 48v dc power

Posted: Fri Sep 02, 2016 1:38 pm
by SystemErrorMessage
I once hooked my CCR1036 to a regulated PSU (the one you use to power things in electronics) While waiting for a new one. I wouldnt recommend doing this because the PSU itself uses 60W from just being turned on. An example would be the rigol DP832A.

Just use the suggested voltage or the voltage you see on the CCR's PSU or in the system health. Make sure not to impose a current limit (or set it to max)

Re: ccr1072 and 48v dc power

Posted: Fri Sep 02, 2016 9:27 pm
by popcorrin
The 1036 and the 1072 have totally different power supply circuitry. Hooking up a 1036 to dc power was a breeze but if you take a look at how the 1072's power supplies connect to the board you will see that there is more than just positive and negative.

Anyone at mikrotik have any insight on how to power a 1072 from dc power?

Re: ccr1072 and 48v dc power

Posted: Fri Sep 02, 2016 11:55 pm
by SystemErrorMessage
If you show a picture of where the inputs are for the CCR1072 it could help.

Edit: i went around looking for images but cant find one that is confirmed. If it uses some kind of hard card slot (like PCI for instance) than it is a matter of finding out which connection is power and which are data. For this i suggest a multi meter/oscilloscope set for voltage.

If it is using a cable through some slot than that is easier to measure, using the same method of multi meter/oscilloscope, find out which one is data and which one are power. There may be multiple voltage lines so you may need to provide multiple voltages instead to do board so having a multi channel regulated PSU would be helpful. It could be that power regulation has been taken off the board and requires PSU instead to provide necessary voltages.

From my experience its easier with an oscilloscope. Simply connect one probe and not ground to find out the voltages. the positive ones will show a +24V for example and negative ones will show a -24V. So if 2 voltages are the same just one is positive and the other negative its pretty much the positive and negative terminal of the same circuit. If it is a data terminal you will see digital signals on your scope. You cant do this with a multi meter, you need a grounded oscilloscope for this. Dont connect the ground probe to avoid a short or some crazy thing happening as you dont know which is what.

There is also possibility of 2 of the same voltages in parallel (for redundancy and load balance). However if the voltage source is the same from your own PSU (1 cable split into 2) than you can accommodate this.

Re: ccr1072 and 48v dc power

Posted: Thu Oct 13, 2016 10:06 pm
by popcorrin
The ccr1072 seems like a router very well suited for the data center. I'm surprised there isn't a dc option.
I'm also surprised no one from mikrotik wants to address this. I would be in the market for a handful of these if we could find a reliable dc powering option for these.

Not really look for some hack that might work.