I received the pack and head last week and have since had 2 shoots with it. Paired with the medium octabox with grid, I've been able to trip the thermal breaker on the Z2500 pack 5-6 times already.
A little more detail please?
I'm shooting both with the Hasselblad and the Nikon. The H3DII-31 needs more power since it's base ISO is 100. Additionally the medium octabox is probably the least efficient light modifier I own. It has an internal baffle to even out the light and then has to spread over the fabric at the softbox face. On top of all this, it's gridded to control spill, albeit not a terribly tight grid. I've been shooting this modifier with the Z2500BTH (BTH stands for bi-tube head) at 1/3 to 1/2 power. The recycle times are just fine. Very tolerable. But the thermal tripper is driving me nuts.
I asked Joe at PCB (Paul C. Buff) and he says there's a thermal breaker that trips when the unit overheats. You can't turn it back on until the unit cools down enough.
Putting a fan on it didn't help. Not even at full blast. We're talking gale-force winds from 1-2 feet away.
The only thing I can think of is to turn down the power even more. Obviously I'd probably be better off with any other modifier. Even the gridded beauty dish. I'll do some more tests and see what I can get away with. I was shooting at f/11 or f/13 yesterday with the D3 and I don't need that much depth of field. I can potentially stop down to f/9 and see what kind of power levels I can use to get faster rates of shooting.
The pack works well. The bi-tube head is blinding at any power. At full power it's 2500Ws of punch. The recycle times are plenty fast. It's just the tripping issue. If it is going to trip like this as often as it does, it really ruins my mojo... more importantly it ruins my model's mojo! Part of the reason I got it was because I'm too often tripping the breaker on the White Lightning X3200.
As an aside, I'm not sure what I'm going to do now that I have the Z2500BTH, X3200, B1600, and 3xB800. I suppose I'll keep them because they're insanely useful for workshops and not having to remove modifiers from the lights. Yeah, I'm super lazy but hey, I don't feel like parting with my lights... not yet at least!
The build of the Z2500 is interesting. It's small. It's light. It's got more plastic parts than my X3200 which feels like it's an older Russian tank. The controls on it are highly reminiscent of the X3200 though. I love the fact that it retains the RJ45 jack so I can still use the RadioPopper JrX from afar.
The internal fans feel like they're pretty strong. I might have to look up the schematics on the fans to figure out how an external fan can supplement the airflow.
Truthfully I beat on the pack. Hard. I shoot fast because lately I've been shooting constant light with the Mole-Richardson and well, shooting with the studio gate open. I think it's just my style. If I can figure out a way to use the Z2500 to suit my style, I might just have to return it... it needs to conform to me. Not the other way around.
On that note, I do have to say the following. Digital has changed the way we shoot. If older/legacy equipment can't keep up with faster frame rates, then they should be updated. Shooting more frames isn't a fad. It's a result of digital photography and it ain't going away.
What about the head? It's a BTH, it's got 2 tubes. It has two plugs, one of each go into each of the outlets on the pack. This allows for faster refresh rates and also the option to plug into another pack for 5,000Ws of power. I am honestly not sure when and if I'll ever need 5,000Ws of power but if I fork over another $800, I'll have a 5,000Ws system that will probably refresh even faster!
Oh and the head is light. Absurdly light. Probably because it's just a box with 2 rings on it. There aren't any components to my knowledge inside the box other than basic circuitry for the rings. Of course it's more complicated than that but most of the electronics are in the pack and not in the head. It is odd putting that head onto a C-stand and then not having to sandbag the rig.
Color consistency? Nothing to report. I haven't had and generally don't have assignments that need color-consistency. I haven't noticed anything "off" just yet. I've heard they do swing some 500 Kelvin on power adjustments... yeah, that's a lot.
Overall the pack is exactly what it is advertised to be. No surprises there. Just wish I could race it a little more without tripping the thermal breaker. More on this later!