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.
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.