Tue Jan 05, 2021 3:07 am
Well - maybe the Mikrotik netPower 16P might not be what I want.
The netPower 16P has two DC connectors.
- A 24-Volt DC connector
- A 48-Volt DC connector
From what I am discovering:
- If you want to run 24-Volt POE devices , then you need the 24-Volt DC powered up using an external 24-Volt DC system.
- If you want to run 48-Volt POE devices , then you need the 48-Volt DC powered up using an external 48-Volt DC system.
- If you want to run both 24-Volt POE devices and also 48-Volt devices , then you need both the 24-Volt and 48-Volt DC connectors both powered up at the same time.
*** It appears that there is no built-in 48-Volt to 24-Volt voltage regulator inside the netPower-16. Thus If you have a an external 48-Volt DC system , then you are limited to only powering 48-Volt POE devices.
Another much more potential serious issue is the following:
- When powering the netPower-16P from my -48 telco-grade DC system, I measure 48 Volts between my rack-mount chassis ( my equipment shelter ground ) and anything metal on the Mikrotik netPower-16P. This includes the ground screw on the Mikrotik netPower-16P !!!
Thus , I suspect if I connect a ground wire from the Mikrotik netPower-16P to my NOC equipment ground or chassis ground , the results will be smoke and fuses will blow !!!
Also , I assume that if I connect any data cables which have a grounded-shield , that smoke and fuses will blow !!!
Soooo, in summary , the netPower-16P can never be connected to normal standard -48 telco power ( or you risk smoke and blowing fuses ). Note, normal telco 48-Volt systems are positive ground. The Mikrotik netPower-16+ is negative ground.
What in the heck were the Mikrotik hardware designers thinking when they designed the power input electronics on the netPower-16P ???
So, IMO, the Mikrotik netPower-16P is almost a useless devices because of the following:
A) - The netPower-16P should be DC power input leads isolated from ground/chassis-ground.
With isolated DC inputs, the user can then use the netPower-16P on standard-telco neg 48 DC power systems ( positive ground ).
With isolated DC inputs, the user can then use the netPower-16P on +48 volt DC power systems ( negative ground )
With isolated DC inputs, the user can elect to use no ground and just power with 48 Volts , and optionally ground the chassis.
B), The netPower-16P should be able to be powered using a single 24 or a 48 volt DC power system - NOT BOTH AT THE SAME TIME.
C), IMO - the Mikrotik netPower-16P should never be used with any normal standard telco neg-48-volt devices ( neg-48 volt routers or switches ) , because there is a serious potential to smoke and blow fuses if you connect any cables with a shield or ground between the two devices.
Will somebody please confirm my findings or correct me if I am wrong.
North Idaho Tom Jones