To answer your queries:
1) As per my knowledge, there is no zone concept in QFX series devices as seen in MX. One reason why I believe this to be true is, the power supplies are 1+1 redundant. The device is capable of working on a single power supply and there is no load sharing as far as I am aware of.
2) Yes, you can remove a PEM with the other PEM in its slot (PEMs are hot-insertable and hot-removable). At a given point in time, the chassis should have one healthy PEM inserted in the PEM slot. As mentioned above, the power supplies are 1+1 redundant.
3) If the device has a working and healthy power supply inserted in one of the PEM slots, the device stays up.
4) In case you want to inter-change the PEMs in their slots, you can choose to do this one PEM at a time. If you do not want your device to undergo a shutdown, please use a spare third PEM to achieve this seamlessly.
5) I believe both AC and DC power supplies are 1+ 1 redundancy which makes it, NO. There is no specific AC DC type that will change this rule.
6) You need not change both the PEMs in slots to check the issue with one PEM. In case there is an issue with both PEMs, the device is taken down in an ideal case.
The below links might help you with replacements(or even in swap test):
Hope this helps 🙂
Please mark "Accepted Solution" if this helps you solve your query. Kudos are always appreciated.
Power supplies should be redundent to each other not having certain power zones to serve.
If this solves your problem, please mark this post as "Accepted Solution.
Verify the status of PEM and also if the PEM airflow direction matches the chassis:
show chassis hardware | match Power
show chassis environment | match Power
show chassis environment pem
Verify that the airflow direction on the power supply handle matches the direction of airflow in the chassis. Ensure that each power supply you install in the chassis has the same airflow direction. If you install power supplies with two different airflow directions, Junos OS raises an alarm. If you need to convert the airflow pattern on a chassis, you must change out all the fans and power supplies at one time to use the new direction.
Hope this helps.
Please mark "Accept as solution" if this answers your query. Kudos are appreciated too!
the QFX will be able to run from one power module, these are hot swapable, as long as you keep one power unit the switch will not go offline.
Hope it helps,