Issue

I need to balance my load; how do I identify which receptacle maps to which phase on the PDU on the rear of SBP16KRMP4U-HW so that I do not overload any one phase?


Product Line

Single Phase Service Bypass Panels


Environment

SBP16KRMP4U-HW (all serial numbers)


Cause

SBP16KRMP4U-HW is primarily used with Symmetra LX UPS systems.  The load attached to a Symmetra LX UPS must be well balanced across both output phases.  Failure to do so could cause one of the phases to become overloaded and enter a bypass state even if the load is less than the total frame rating.  Each phase should supply roughly the same amount of current so 120 volt loads must be distributed properly by the user to ensure this.


Resolution

SBP16KRMP4U-HW provides the following standard NEMA outlets:

(3)  L5-20R (3-pin twist-lock)

(1)  L14-30R (4-pin twist-lock)

The L5-20R outlets provide single-phase 100, 110, or 120v AC (Phase-Neutral) service. These outlets are sourced consistently from specific phases (legs) on the service bypass panel.  The following diagram illustrates which receptacle is powered by which phase.







The UPS is capable of displaying the load on each phase; this information can be accessed either via the front LCD display or via the included network management card.  The information in this document, in addition to the load percentages given by the UPS display, should be enough to balance the load properly across the output phases.

Released for:APC Netherlands