The problem is in the cold

As soon as the frost began. On the street -25 C. I stopped letting it on the web and via ssh (it enters but only runs on reboot and show sta)

ePMP 1000. Version 3.5.1 3.5.5 4.4.2

Hmmm you're getting very close to the maximum rated temp range specifications "-30°C to +60°C (-22°F to +140°F)"

ePMP AP radios use more power when it's cold to power a small internal heater. Depending on the PoE, power supply, and cable length and guage used, you may need to supply it more power.

Please see THIS article on operating ePMP radios in sub freezing tempuratures.

Caution: this is long and has several close to irrelavent sections.

The heater only runs on power up, it should not run otherwise as specified in the user guide. Your poe port must be able to supply 56w of power, if not then you can have brown out issues. Your cable should be 24awg (22awg is better but not required) pure copper, if using CCA then you again will run into cold weather issues as the cable may not make good contact in the crimp on connectors and cold fractures in aluminum cabling are excerbated by the fact that aluminum shrinks more than copper.

All electrical equipment uses more power in cold environments due to the fact that as the components get cold thier resistance increases slightly. This continues until breakover temperatures where the material becomes a super conductor. The amount of extra power consumption is fairly small but depending on your AP load, you may be close to what your poe port can provide. If possible, try bypassing the poe on the switch and using a cambium power supply, these are 60w nominal but I have pulled 70w with it only getting slightly warm, the cable if using a pure copper 24awg cable in power over all four pairs, then 120w is fine. If like us you are using a DC power system, then the poe injector could be an issue and there are lots of injectors that just do ping 4,5 and 7,8 for power but are gigabit compatible. (Disclaimer: Niether I or my company are affiliated with PacketFlux, we just like thier injectors) We are using PacketFlux Gigabit injectors at our towers and once your set the internal pins correctly, they work great. Bonus is that you can power two differing voltages and still provide common timing over power which we use to provide for GPS failures. This has saved us from climbing a tower in the late evening in -25 weather to change a defective GPS antenna, which at those temperatures means the new one may get damaged just installing it! 

We have epmp1000's , force180's and force200's out there in -35 to -50 without issues due to cold while operating. However if performing a new install or radio replacement, we found a radio that cold will take about an hour before it actually boots properly. So we created a cold weather policy to keep radios inside and not in the truck over night. radios are to be kept in the truck with the truck heater on to keep the radio warm and we wait to the last minute to mount the radio. once the radio boots, it can cool down and it will stay running. We also hand out as part of our welcome kit a notice about severe cold bootup times saying that a power outage to the radio may cause extended downtime and provide a chart to show the amount of time at temperature to boot up and the amount of time needed to cool the radio at those temperatures to cause the bootup delay. This chart is also used by our support staff to determine if a tech should be sent to that client or to have the client wait. We also suggest that every client purchase a UPS just for the radio and wifi to prevent issues with power outages and power bumps (which we see a lot of here).

1 Like

@afetisov wrote:

As soon as the frost began. On the street -25 C. I stopped letting it on the web and via ssh (it enters but only runs on reboot and show sta)

ePMP 1000. Version 3.5.1 3.5.5 4.4.2


Hi,

Could you please reach me at fedor.trutsko(at)cambiumnetworks(dot)com?

And I will try to help you with the issue.

Thank you.

1 Like

@Douglas Generous wrote:

Caution: this is long and has several close to irrelavent sections.

The heater only runs on power up, it should not run otherwise as specified in the user guide. Your poe port must be able to supply 56w of power, if not then you can have brown out issues. Your cable should be 24awg (22awg is better but not required) pure copper, if using CCA then you again will run into cold weather issues as the cable may not make good contact in the crimp on connectors and cold fractures in aluminum cabling are excerbated by the fact that aluminum shrinks more than copper.

All electrical equipment uses more power in cold environments due to the fact that as the components get cold thier resistance increases slightly. This continues until breakover temperatures where the material becomes a super conductor. The amount of extra power consumption is fairly small but depending on your AP load, you may be close to what your poe port can provide. If possible, try bypassing the poe on the switch and using a cambium power supply, these are 60w nominal but I have pulled 70w with it only getting slightly warm, the cable if using a pure copper 24awg cable in power over all four pairs, then 120w is fine. If like us you are using a DC power system, then the poe injector could be an issue and there are lots of injectors that just do ping 4,5 and 7,8 for power but are gigabit compatible. (Disclaimer: Niether I or my company are affiliated with PacketFlux, we just like thier injectors) We are using PacketFlux Gigabit injectors at our towers and once your set the internal pins correctly, they work great. Bonus is that you can power two differing voltages and still provide common timing over power which we use to provide for GPS failures. This has saved us from climbing a tower in the late evening in -25 weather to change a defective GPS antenna, which at those temperatures means the new one may get damaged just installing it! 

We have epmp1000's , force180's and force200's out there in -35 to -50 without issues due to cold while operating. However if performing a new install or radio replacement, we found a radio that cold will take about an hour before it actually boots properly. So we created a cold weather policy to keep radios inside and not in the truck over night. radios are to be kept in the truck with the truck heater on to keep the radio warm and we wait to the last minute to mount the radio. once the radio boots, it can cool down and it will stay running. We also hand out as part of our welcome kit a notice about severe cold bootup times saying that a power outage to the radio may cause extended downtime and provide a chart to show the amount of time at temperature to boot up and the amount of time needed to cool the radio at those temperatures to cause the bootup delay. This chart is also used by our support staff to determine if a tech should be sent to that client or to have the client wait. We also suggest that every client purchase a UPS just for the radio and wifi to prevent issues with power outages and power bumps (which we see a lot of here).


I disagree with the bolded statement. If you look into computer CPU's and overclocking, when placed under a pelter/TEC or Ln2 cooling, you can run the same settings with less voltage than at room temp. 

Yes different kind of parts, but still electrical.

I do recall years back that cambium did state that even SMs have a warm up cycle to thaw if frozen on power up, i think they patched it in 3.0.1ish firmware. We had SMs having that issue that winter.


@Skullzaflare wrote:


I disagree with the bolded statement.



Ohms law, along with the basic principles of semiconductors, disagrees with it as well. Nothing against his post as Douglas had some good points. Thank God, I do not have to deal with such temps. 

They did not fix it. Yesterday at -27 I switched (froce 180) from AP mode to SM and lost equipment. The port is up, but there are no MAC addresses. Only reboot helped. Epmp 1000 also hung. MAC only pinged arping, IP did not ping.

For you guys that are having cold related issues... I wonder what is different between our installations and yours?  We are in Northern Canada, and we get lots of -30 -40 temperatures here, and colder. Our record low here is -56c (-70 F) and we don't experience cold related problems with Cambium - neither the old FSK or the ePMP.

I am wondering...  are you using the Cambium supplied power supplies (30v and 56v) or are you using generic 24v power supplies? or using 24v POE from a switch or router?

We use the one that comes with the kit.


@afetisov wrote:

We use the one that comes with the kit.


OK, sounds good. I just thought that might be a cause, but apparently not.  I wonder what's different on our systems here... we don't use Force180s, but our ePMP1000s and Force200s and Force3000s live through -30c -40c -50c temps with no problems.

Hi,

Do you have any support case opened with our support team?

As a general fact we have thousands of units deployed in the harshest environments so cold issues is something out of ordinary.

Thanks,

Dmitry