Field Engineer’s Notes (From the Trenches)
The “Gotcha” is Backplane Load Calculation & Battery Presence.
Load Budget: The 18A @ 5V is the headline, but the reallimit is the total wattage (roughly 90W for +5V + ~19W for ±12V = ~110W total).
- A fully loaded rack with IC697CPU772 (1.5A), 6 x IC697ALG230 (0.3A ea), 2 x IC697MDL740 (0.5A ea) pulls ~5A + logic. Easy fit.
- If you add high-density discrete output modules (IC697MDL753 x 4 banks) with heavy resistive loads externally poweredbut with high backplane logic draw, you can approach 15-16A.
- Symptom of Overload: “FLT” LED On, CPU may go to STOP or show “Power Loss.” Check the total backplane current draw in the hardware config report before adding modules. If >16A continuous, consider the IC697PWR711 (30A version) or splitting I/O into an expansion rack.
Battery Alert: The PWR710 charges the battery, but the CPUdecides when “BAT LOW” is reported. If you see “Battery Low” on the HMI but the PWR710’s BATT LED is Green, the battery itself is likely dying (weak cell). Replace it with power ONto preserve CPU RAM. If the PWR710’s BATT LED is Off with a good battery installed, the charge circuit in the PSU may be dead (rare, but then the battery won’t last long uncharged).
AC/DC Selection: No jumpers. It auto-senses. Just land the wires (L/N/PE for AC; +/–/Chassis Gnd for DC). Ensure PE (Ground) is landed—the EMI filter needs it to meet emissions specs and for safety.
Real-World Applications
- Combined Cycle GT Mark V/VI (90-70 Rack): A in Slot 0 powers the TCEA (CPU), TCQA (Analog I/O), and TCTA (Comm) modules. A second in the redundant slot provides N+1. During a station battery switchover (120V AC to 125V DC), the wide input range kept the rack alive with zero scan interruption.
- Pharmaceutical Batch RX7i (IC698CHS117): powering an IC698CPE010, IC698ETM001, and mixed analog/digital I/O. The +12V rail drives the IC698ALG220 excitation. The “FLT” LED caught an overloaded backplane (tech added an extra 16-pt output card pushing draw to 17.5A) during commissioning before it caused a runtime trip.
High-Frequency Troubleshooting FAQ
Q: “PWR” LED is OFF, but 120V AC is landed at the terminal block and confirmed with DMM.
A: Input Wiring or Internal Fuse.
- Verify Line and Neutral are landed on the correct terminals (check silkscreen: usually L & N). Verify voltage at the terminal screws(not just at the wire end—loose screw = no contact).
- Check the Internal Input Fuse (Often accessible through a small hatch on top or side of the PSU, labeled F1). If blown (open circuit), replace with GE-specified slow-blow fuse (usually 3.15A or 5A, 250V). If it blows again immediately, the PSU has an internal short (capacitor failure common on 15+ year old units)—replace the module.
- Ensure PE (Ground) is landed. Some revisions won’t power up if PE is floating (safety interlock on EMI filter).
Q: “PWR” is Green, but “FLT” is Red. CPU shows “Power Loss” or won’t go RUN.
A: Backplane Overload or Output Fault.
- The +5V rail is sagging or the overcurrent protector tripped.
- Test: Power down the rack. Remove all I/O modules (leave CPU and PSU). Power up. Does “FLT” go Out and “PWR” stay Green? If yes, a module is shorting the 5V backplane. Re-insert modules one by one until FLT returns to identify the culprit.
- If FLT stays Red with onlyCPU + PSU: The PSU’s +5V regulator may be failing (aged capacitors). Try the redundant PSU if installed; otherwise replace the .
- Check the Battery—a shorted battery (rare) can pull the +5V rail down. Temporarily disconnect the battery cable from the CPU (or PSU depending on arch) to see if FLT clears (CPU RAM will be lost if no power—do this only to diagnose).
A: Yes. The is fully compatible with the RX7i Universal Backplane.
- It provides the +5V, +12V, -12V required by RX7i CPUs (IC698CPExxx) and I/O (IC698xxx).
- The only caveat: If you need >18A @ 5V (heavy RX7i I/O load), you may need the IC697PWR711 (30A) or the IC698PSA100 (RX7i native PSU, 100-240V AC in, 20A @ 5V). For most standard RX7i configs (CPU + ETM + 3-4 I/O cards), the is sufficient and cost-effective.
Please note: The listed price is not the actual final price. It is for reference only and is subject to appropriate negotiation based on current market conditions, quantity, and availability.
