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Portable power packs

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Jonathan Johnson:
New product offering from Eaton/Tripp-Lite: https://tripplite.eaton.com/portable-power-station-1000w-lithium-ion-ac-dc-outlets-usb-charging~GC1000L

This is a 1000w Lithium Ion Phosphate power pack with sine wave output and 1048Wh reserve capacity. Looks like it could be a handy unit.

However, looking at it, I suspect that the holes for the ground pin of a three prong NEMA 5-15 plug are just that -- holes. If the equipment grounding conductor is indeed left unconnected (so multiple devices could have different ground potentials) and not bonded with neutral, what are the implications of safety when multiple devices are connected, and what is the potential for ground loops through signal cables if used for powering audio equipment?

TJ (Tom) Cornish:

--- Quote from: Jonathan Johnson on January 17, 2024, 05:11:01 PM ---New product offering from Eaton/Tripp-Lite: https://tripplite.eaton.com/portable-power-station-1000w-lithium-ion-ac-dc-outlets-usb-charging~GC1000L

This is a 1000w Lithium Ion Phosphate power pack with sine wave output and 1048Wh reserve capacity. Looks like it could be a handy unit.

However, looking at it, I suspect that the holes for the ground pin of a three prong NEMA 5-15 plug are just that -- holes. If the equipment grounding conductor is indeed left unconnected (so multiple devices could have different ground potentials) and not bonded with neutral, what are the implications of safety when multiple devices are connected, and what is the potential for ground loops through signal cables if used for powering audio equipment?

--- End quote ---
Without knowing anything about this particular product, I suspect itís not dissimilar to a Honda EU1000 in theory - no bonding and a very small <15A circuit means not that much potential for errant ground noise. All 3-wire devices will be grounded to each other through the ground wires in the power distribution gear, and any 2-wire devices will float or use their chassis grounding or whatever.

We discussed the safety and noise aspects of this (small Honda unbounded generators) at some length maybe 10 years ago here. The consensus was that in an unbonded system with no earth ground either, there really isnít much of a viable alternate (aka undesirable) path for shocking, so the lack of GFCI protection wasnít particularly concerning, as any shock would have to be line to neutral, which as far as the GFCI knows is desirable current and it wouldnít trip anyway.

From a noise standpoint, ground loops through audio gear need to be long enough for the induced current to raise the ground at one point significantly relative to another point. It seems unlikely to me that in a 1000w peak system there would be enough current or enough cable length to cause material issues.

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