My question really stems from some research I am doing on surge protection devices. (SPD) Most consumer level uninterruptible power supplies / battery backups (UPS) provide some level of surge protection, but according to what I have read, it is not the best protection. It would then seem best to plug a UPS into a quality surge protector. However, some individuals say that that can cause one or both to fail. The stated reason is that you cannot put MOV's in a series, and that is what you are essentially doing when you plug a UPS into a SPD. This would be the same as plugging one surge protector into another.
There seems to be some misinformation about this, as a bulletin from Eaton Corp. recommends putting a surge protector upstream of your UPS.
...any overflow of juice on the power line will be attracted to the MOVs (generally three MOVs to a protector) and drawn to a ground area. The rate at which electricity flows is enough that this can bounce between the two surge protectors, negating any and all protection and even cause some models to shut down.
There seems to be some misinformation about this, as a bulletin from Eaton Corp. recommends putting a surge protector upstream of your UPS.