Safety: Warnings
Total Power Off
1.Set the Symmetra PX UPS System Enable switch to Off.
2.Set the DC Disconnect breaker of each Battery Enclosure to Off.
3.Set the PDU Main Input (A) switch to Off.
4.If applicable, set the PDU Bypass Input (B) switch to Off.
5.If applicable, set the PDU Cross Tie Output (X) circuit breaker to Off.
6.Set all upstream utility circuit breakers feeding the PDU to Off.
7.Disconnect the batteries in the Battery Enclosure and any XR Battery Enclosures by pulling them out to the red disconnect line.
Electrical Hazard
Hazardous, live parts may exist inside the PDU because of the Symmetra PX UPS inverter even when the AC power is disconnected. Test any electrical parts before touching them.
Emergency Power Off (EPO)
Hazardous voltage from the branch circuit must be isolated from the 24VAC, 24VDC, and contact closure. 24VAC and 24VDC are considered Class 2 circuits as defined in Article 725 of the National Electrical Code (NFPA 70) and Section 16 of the Canadian Electrical Code (C22.1).
A Class 2 circuit is a source having limited voltage and energy capacity as follows:
a.If an Inherently Limited Power Source, voltage and energy are limited to less than 30VAC, less than 30VDC, and 8A.
b.If not an Inherently Limited Power Source, voltage and energy are limited to less than 30VAC, less than 60VDC, 250VA, and the current is limited to 1000/Vmax. The fuse is limited to 5A if less than 20VAC or 20VDC, or 100/Vmaximum if less than 30VAC or 60VDC.
If you choose to use a 24VAC, 24VDC, or contact closure connection to the EPO, use one of the following
•CL2 Class 2 cable for general purpose use
•CL2P Plenum cable for use in ducts, plenums, and other space used for environmental air
•CL2R Riser cable for use in a vertical run shaft from floor to floor
•CL2X Limited Use cable for use in dwellings and for use in a raceway
•For installation in Canada, the cable should be CSA Certified, type ELC
If you do not use a CL2 cable, route the EPO wiring in conduit that does not contain any branch circuit wiring.
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