Yokogawa AEP7D-20 Primary Power Supply Bus Unit

Suffix Breakdown & Model Matrix

• AEP7D: Primary Power Supply Bus Unit platform
• -1: 100-120 VAC input configuration
• -2: 220-240 VAC input configuration
• -4: 24 VDC input configuration
• 5: Basic type without explosion protection
• 6: ISA G3 option, non-explosion protected
• E: Basic type with explosion protection
• F: ISA G3 option with explosion protection

Hardware Specifications

Power Distribution Backplane Architecture

Dual-Rail Cabinet Power Segregation

The AEP7D-20 implements a dual-input power distribution topology supporting A and B independent feeds. In normal configuration, A and B rails are routed separately to 7 dedicated output ports per side, maintaining electrical separation across backplane distribution lines.

Within Yokogawa distributed control system environments Yokogawa, this topology is typically used to preserve isolated supply domains for I/O modules, communication gateways, and controller power segments, reducing single-point power dependency within cabinet-level architecture.

Channel isolation behavior aligns with standard DCS practices including:

• Segregated power rails for control and communication subsystems
• Backplane distribution integrity under redundant supply conditions
• Controlled collapse behavior under single-feed failure

Frequently Asked Questions

Q: Can A and B inputs be operated in parallel?
A: Yes. When A and B terminals are externally bridged, a single supply source can feed all 14 outputs. Internal distribution remains separated per port grouping.

Q: Does each output port have independent current limitation?
A: Yes. Each port supports a defined maximum current limit (6 A or 10 A depending on model suffix). Total bus current must remain within primary input rating.

Q: Is hot-swap behavior supported on output loads?
A: The unit itself is passive distribution hardware; hot-swap capability depends on downstream module design and cabinet backplane architecture, not on the bus unit switching element.

Field Installation Guidelines

Power cabling shall be routed with strict separation between A and B input conductors to prevent cross-coupling on redundant feeds. All grounding conductors must terminate at a single-point cabinet earth reference to avoid circulating ground currents across bus rails.

For DIN rail mounting, ensure mechanical locking engagement is fully seated along the full rail length to prevent vibration-induced contact resistance changes. Maintain minimum clearance around power terminals consistent with cabinet thermal zoning requirements defined in system-level installation standards.

Shield terminations for associated control wiring should be bonded at cabinet entry point only, avoiding distributed shield grounding across multiple bus segments.