List of Contributions

The step-down transformer shown in both the Fig 7 & 8 is confusing us. Is it used for stepping down the Primary voltage to 110VAC or 230VAC? Or should we consider this transformer as Isolation transformer as mandatory requirement by Rockwell to feed 1756-PA75 in both grounded-neutral and un-grounded ...

Already Voltage measured are L&N=110VAC, N&G=55VAC, L&G=55VAC. This was checked with local licensed electrician. The question put by them is " Is 1715-PA75 is approved for IT Power grid system?" If yes then we can avoid isolation transformers, but we need to see any documentation from Rockwell where ...

Do you confirm that 1756-PA75 power supply is not suitable for IT power style grids with max ph to ph of 110vac? -------------------------------------------

Hi Philip Thanks for your valuable response. Figure 8 on document 1770-IN041 shows one Step down transformer. Is it External Isolation Transformer? Can we use ungrounded neutral feeding L1 & L2 with 110vac across to be connected to 1756-PA75 without any Isolation transformer? In my case Load is single ...

Dear Experts, One of the Customer at site has Ungrounded Neutral UPS system. Voltage measured are : L&N=110VAC, N&G=55VAC, L&G=55VAC. I am not clear if 1756-PA75 supports Ungrounded Neutral at the Input side without any need for external Isolation Transformer at the Upstream of of 1756-PA75? The ...

How does the switchover happens among the Primary & Secondary AENTRs? How CPU-controls are transferred to the healthy AENTR? Pls. explain in details because page 23 of Manual 715-UM001L-EN-P is confusing to me.

In a 1715 I/O modules in a Duplex Pair i understand that both modules are synchronized simultaneously. The module back plane TAD does not differentiate between Slot A and Slot B. How Slot A and Slot B I/O module of the Duplex pair decides which one is Primary and which one is secondary?

Alternate Question: Rack1 & Rack2 are redundant CPU racks and Rack3/4 are redundant IO racks connected in DLR ring. Considering Rack1 is active and Rack2 is on standby. In this case if my 1756-EN2TR of Rack2 has failed and at the same time 1715-AENTR of Slot0 failed, then does all my IO modules in Rack3 ...

Pls. confirm if below 1715 modules operate in Sinking model only: 1715-IF16 Analog Input Module 1715-OF8I Analog Output Module 1715-IB16D Digital Input Module