Phase Sources on Symmetra LX PDU Panel SYAPD1

Issue

I need to balance my load; how do I identify which receptacle maps to which phase on my SYAPD1 PDU panel so that I do not overload any one phase?


Product Line

Symmetra LX


Environment

Split phase UPS systems only (SKU ends in P)


Cause

Being a split phase UPS system, 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

The SYAPD1 is the standard PDU Panel provided on rack-mount split-phase Symmetra LX UPSs (100/200v, 110/220v, 120/208v, or 120/240v AC output).  SYAPD1 provides the following standard NEMA outlets:

(2)  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 Symmetra LX.

The L5-20R located on the left of the SYAPD1 PDU Panel sources from Phase 1.

The L5-20R located on the right of the SYAPD1 PDU Panel sources from Phase 2.


 


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.