I'm dealing with an old 400 amp split main Crouse-Hinds panel. A solar installer has asked me about the buss rating so he can determine what he can do with adding a PV system.

All the paper work on the panel is missing and I'm not able to find anything on-line. Some help on this would be appreciated. Please see the image file I added of the panel.

Thanks!

Edit*****

Need the "Continuous Rating"

Byron:

Backfeed BETWEEN the twin 200 Amp C/Bs;

using the tap rules and an adjacent j-box -- suitably large.

You'd end up with twin splice blocks ( Ilsco ? ) and very short 3/0 THHN jumpers interposed between the splice blocks and the circuit breakers.

During the night, the current would shunt around exactly like your current set up.

During daylight, your inverter output(s) would flow out to both panels -- from this center point -- until the meter ran backwards.

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Such a scheme entirely removes the bus calculation from the design. You'll never have so much PV sourced current that it stresses that top copper bus.


http://www.ilsco.com//productcatego...31RZYOsRgUwvNMGDmVHPiZnijY7FLyC%2bjmo%3d

There will be Two separate Bus Kit FLA ratings:

A: Upper Bus Kit; the Bus Kit which feeds the (2) 200 Amp 2 Pole Breakers,

and

B: Lower Distribution Bus Kit, where the 70/100 Amp Frames are Plugged On.

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Ratings for Bus Kit "A" (Upper Bus Kit):

Most likely, the Upper Bus Kit will be rated for 400 Amps Continuous (400 Amps drawn for >180 Minutes), as the Service Disconnect is rated 400 Amps.
The (2) 200 Amp 2 Pole Devices may draw 200 Amps each, and continue to draw 200 Amps steadily until the Sun Supernovas; yet will not trip.

A Residence drawing 400 Amps continuously is unlikely, so the KWH Meter and Meter Socket might be rated as 400 Amp Maximum, 320 Amps Continuous.
The KWH Meter should indicate this on the front label, as:
"CLASS 320".
(BTW, "KWH" = KiloWatt-Hour; referring to the Utility's Revenue Meter).

Fault Bracing for the Upper Bus Kit is likely to be 22KA, but could be as high as 30KA or even 42KA.

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Ratings for Bus Kit "B" (Lower Bus Kit):

The highest Rating which the Lower Bus Kit would be rated for is 225 Amps Continuous (225 Amps for >180 Minutes).
The Lower Bus Kit should be Nominally rated as 200 Amps Continuous (200 Amps for >180 Minutes).

The Bus Tabs (Plug-In stabs for the Over Current Protection Devices), will typically be rated 100 Amps Max., 70 Amps Continuous.

Fault Bracing for the Lower Bus Kit would mimic the Upper Bus Kit: 22KA Nominal; 30KA or 42KA optional.

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Observational Note; this Service Equipment has Copper Bus Kits!!!
(capable of withstanding heavy loads)

Tesla's post covers the Lug and Terminal Block data properly.

-- Scott (EE)