I am not totally clear as to what balanced and unbalanced power means. I plan to find out tomorrow when I speak to my CE. Looking online and doing a search for "balanced power systems" makes me think that it has something to do with the current draw on each phase. Being single phase, I can understand why it cannot be balanced. If I find the true answer, I will post here.
The more important thing is that it seems that with single phase power, you cannot have beyond a specific amount of I/O drawers. Aria From: The IBM z/VM Operating System [mailto:ib...@listserv.uark.edu] On Behalf Of P S Sent: Tuesday, December 22, 2009 9:58 AM To: IBMVM@LISTSERV.UARK.EDU Subject: Re: z890 power: 3 phase vs 1 phase? On Tue, Dec 22, 2009 at 9:49 AM, Aria Bamdad <a...@bsc.gwu.edu> wrote: The question below was asked back in May with no real answer. I recently ran into a section in an IBM z10-BC systems assurance document (SA08-006) that says: 3.5.1 Important Power Selection Considerations As you select features for your z10 BC server, be aware of the following when choosing server power: . If you choose single phase power, you can have a maximum of two I/O drawers. . If you choose single phase power, you will have unbalanced power. . If you choose three phase power, you may have either balanced or unbalanced power, depending on server configuration. . If you choose three phase power, you can guarantee balanced power by selecting FC3002, Balanced Power Plan Ahead. This feature adds two more Bulk Power Regulators to each side of the power supplies, assuring adequate and balanced power for all possible configurations. So, something like the above may apply to a z890 as the original question referenced. What is "unbalanced" power? The Senate without the House? Congress without the Supreme Court? Seriously, though -- what does it mean?
