Epmp 3000 and ptp 550 heaters

I am told the epmp 3000 and ptp 550 units have built in heaters for colder temperatures. If so, do they kick in when the device has been powered down to bring the components temp back up before they turn on and then turn off once operating temps are reached or do they kick in even when a device is running for a long time but encounters colder temperatures?

Its both. There is a concept of a cold start feature where the units are warmed up before it boots up and also a run time function for when temp really drops low despite the unit running.

@Sakid_Ahmed, thank you for your reply… so if this is the case what is the negative temp when they kick in while the unit is running?

Basically heaters keep temp of main components above 0C.
There is a configurable threshold (5C default) to kick in heaters.

So once the heaters get the components above 0, the unit can fully power up and does the devices running temperature keep the heaters from turning on? When heaters run is this the max power consumption that is listed in spec sheet?

Yes, once system is ON components warm up themselves. Heaters are turned on dynamically if needed.

For the run time heating only half of heating power is used. It is guaranteed that power budget is met even if system is fully loaded.

During coldest Chicago winter in Jan 2019 temp dropped below -23F (-30C).
Local WISP sites with ePMP 3000 and F300s were monitored for stability.
No outages were reported.

@bveselov can one get info on what wattage is used for the heaters when they run at startup and when device is running?

Also could one put in a script for the heaters when they kick in to be a lower thresh hold than 0 degrees C?

@DigitalMan2020 basically it is not recommended to change heating config by customers.
If you’re suspecting a temp related issue, like instabilities at low temperatures, please open a support ticket. In this case potential heating config adjustments can be added to official release to improve stability for all other customers.

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think of the power requirements like this: the brick puts up to 60w on the ethernet cable if needed so plan for this even though I have not seen our radios draw more than 0.9A at 24v yet. You shouldnt consider using an inverting UPS to backup your radios, a direct DC system is much better and provides longer run time per AH of backup supply. just plan on a power supply that is at least twice the capacity of the system draw, more may be needed if you provide a large AH battery bank. This is to provide enough supply power to recharge the batteries at a reasonable rate yet not too fast as to cause gassing or excessive heating of the batteries.

The heaters run as needed from 0degC and colder, at -40degC they are practically on all the time and since we commonly get that cold I can attest that the radio will stay operating but that is the least of your issues at that cold. Fully charged batteries freeze at that cold and lithium batteries aren’t much better.

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@bveselov Is there a way to monitor the internal temp for a WISP or is it possible for cambium to see if there is an overheat issue on an ePMP 3000. My question becomes the opposite of the forum although it’s the only forum that I found that discusses the internal temp of a radio so I thought I’d check before opening a ticket…

I do believe there is an OID for CPU temp, you will have to walk the SNMP OID tree with all of the MIBS installed to get it.

The heater only heats the CPU chip to ensure proper bootup during cold weather startups and is only run for a short time. If you’re monitoring the current draw on the AP, the temperature is blow 32F/0C you will see a larger than normal current usage for a couple mins then it will drop down to normal bootup levels.

If you are seeing high temps reported on the radio status page then you need to talk to support directly as something is definitely wrong.

Thank you for the response. I didn’t think there would be an OID for the internal temp as it’s not displayed anywhere in the radio that I can find. I will give it a shot though. I’m not sure what you mean by high temps on the status page though as I don’t see anything about internal temp on the status page. @Sakid_Ahmed

Sorry, I was thinking about the wrong interface, epmp does not show temperature but will send error logs with high temperature warnings.

You can read or write these. This will give you the current startup heating figures and be able to set them to match your area temperature requirements.

SystemConfigPreheatStopTemp will tell you what temperature it is trying to reach and systemConfigPreheatStopTimeout will give you how long the preheater has left to run.

There are more OIDs than what the MIB specifies, so walk your radio with all of the canopy and cambium mibs loaded.

Remember to download your tech data when it does odd things and open a ticket if you think there is a hardware issue.