The Yokogawa AEP7D Primary Power Supply Bus Unit is designed to distribute primary power to multiple control system components installed within the same FIO cabinet. The unit supports two independent power inputs (A and B) and provides seven output ports for each input, allowing either redundant power distribution or a single-input configuration with up to fourteen output circuits. Proper installation, wiring, grounding, and commissioning are essential for maintaining reliable power distribution and ensuring continuous operation of Yokogawa control systems.

Contents

• 1. AEP7D Power Supply Bus Unit Overview
• 2. Technical Features
• 3. Typical Industrial Applications
• 4. Installation Planning
• 5. Hardware Inspection
• 6. Installation Environment
• 7. Bus Unit Mounting Procedure
• 8. Primary Power Wiring
• 9. Grounding Requirements
• 10. Power Distribution Connections
• 11. Wiring Verification
• 12. Commissioning Procedure
• 13. Functional Testing
• 14. Preventive Maintenance
• 15. Practical Installation Case
• 16. Frequently Asked Questions

AEP7D Power Supply Bus Unit Overview

The AEP7D distributes primary power throughout a Yokogawa control cabinet. It accepts two independent input power sources identified as Input A and Input B. Each input feeds seven dedicated output ports. When Inputs A and B are connected in parallel, the unit can distribute power through fourteen output ports from a single power source. Models are available for 100–120 VAC, 220–240 VAC, and 24 VDC input supplies. :contentReference[oaicite:0]{index=0}

Technical Features

• Dual independent power inputs (A and B)
• Seven output ports for each input
• Fourteen outputs when inputs are paralleled
• Available for 100–120 VAC, 220–240 VAC, or 24 VDC
• Maximum input current up to 20 A AC or 30 A DC depending on model
• Cabinet-mounted power distribution design

Typical Industrial Applications

• CENTUM VP control cabinets
• FIO cabinet power distribution
• Redundant DCS power systems
• Oil and gas facilities
• Chemical processing plants
• Power generation systems

Installation Planning

Engineering documentation should be reviewed before installation to ensure correct power allocation.

• Verify cabinet drawings
• Confirm power source ratings
• Review load calculations
• Prepare cable schedules
• Inspect installation location

Hardware Inspection

• Verify model number
• Inspect enclosure condition
• Check input terminals
• Inspect output terminals
• Verify mounting hardware

Installation Environment

• Maintain adequate ventilation
• Avoid excessive humidity
• Protect against vibration
• Prevent conductive dust accumulation
• Maintain cabinet cleanliness

Bus Unit Mounting Procedure

1. Disconnect cabinet power.
2. Install the AEP7D in the designated cabinet location.
3. Secure all mounting hardware.
4. Verify mechanical alignment.
5. Inspect all terminal clearances.
6. Confirm accessibility for maintenance.

Primary Power Wiring

Power wiring should comply with approved engineering drawings and applicable electrical standards.

• Connect Input A power supply
• Connect Input B power supply if redundancy is required
• Verify conductor sizing
• Tighten all terminals correctly
• Label all incoming feeders

Grounding Requirements

• Connect protective earth securely
• Maintain low earth resistance
• Avoid multiple grounding paths
• Verify cabinet bonding
• Inspect grounding continuity

Power Distribution Connections

VERIFY INPUT POWER
CONNECT INPUT A
CONNECT INPUT B
VERIFY OUTPUT PORTS
CHECK LOAD DISTRIBUTION
LABEL ALL CIRCUITS

Wiring Verification

• Verify terminal identification
• Measure insulation resistance
• Inspect conductor polarity
• Confirm load assignments
• Review engineering documentation

Commissioning Procedure

• Apply input power
• Measure output voltages
• Verify redundancy operation
• Check downstream equipment
• Record commissioning results

Functional Testing

• Verify all output ports
• Test redundant power transfer
• Confirm voltage stability
• Monitor connected equipment
• Validate cabinet operation

Preventive Maintenance

• Inspect terminals every six months
• Retighten power connections
• Inspect grounding annually
• Clean cabinet interiors
• Review load distribution periodically

Practical Installation Case

During commissioning of a refinery control cabinet, engineers observed that several FIO modules remained unpowered despite normal incoming AC voltage.

Inspection showed that Input A had been wired correctly, but the outgoing feeder supplying one group of output ports had not been tightened after installation.

After tightening the terminal and verifying every output circuit:

• All downstream modules powered up successfully.
• Redundant power operation was verified.
• No abnormal voltage drop was detected.
• The cabinet entered normal service without replacing the bus unit.

Frequently Asked Questions

What is the primary function of the AEP7D?

The AEP7D distributes primary power from one or two power sources to multiple devices installed within the same Yokogawa control cabinet. :contentReference[oaicite:1]{index=1}

How many output ports are available?

The unit provides seven output ports for Input A and seven output ports for Input B. If both inputs are connected in parallel, one input source can supply fourteen output ports. :contentReference[oaicite:2]{index=2}

Which input voltage versions are available?

The AEP7D is available for 100–120 VAC, 220–240 VAC, and 24 VDC input power depending on the model suffix. :contentReference[oaicite:3]{index=3}

Summary: Proper installation of the Yokogawa AEP7D Primary Power Supply Bus Unit requires correct cabinet mounting, secure primary power wiring, reliable grounding, balanced power distribution, and comprehensive commissioning to ensure stable operation and dependable power delivery throughout the control cabinet.