APC Rack PDU Guide: Metered vs Switched vs Basic — Which Do You Need?
A basic rack PDU simply distributes power with no monitoring. A metered PDU adds per-bank or per-outlet power readings. A switched PDU adds remote on/off control per outlet. Here is when to use each type and which APC models to buy.
Basic vs Metered vs Switched PDU: The Quick Answer
A basic rack PDU is a power strip for your server rack with no monitoring or management. A metered PDU adds an LCD display and/or network interface showing real-time power consumption in amps, watts, and kWh per bank or per outlet. A switched PDU has everything a metered PDU has, plus the ability to remotely turn individual outlets on and off via a web interface or SNMP. For most server rooms with 4+ devices, the metered PDU is the sweet spot. For data centers requiring remote reboot capability, the switched PDU is the right choice.
Why Rack PDUs Matter
A rack PDU is not just a fancy power strip. In a professional server environment, the PDU is a critical infrastructure component that determines:
- How many devices you can safely power from a single circuit
- Whether you can monitor power consumption for capacity planning
- Whether you can remotely reboot a hung device without driving to the data center
- How efficiently you use your available power budget
- Whether you meet compliance requirements (SOC 2, HIPAA, PCI-DSS all require power monitoring)
APC PDU Types Explained
Basic Rack PDU (AP Series)
APC basic rack PDUs are heavy-duty power strips designed for rack mounting. They distribute power from a single input to multiple outlets with no electronics, no monitoring, and no management. They are essentially indestructible (no components to fail) and cost the least.
When to use basic PDUs:
- Home labs and test environments
- Remote closets with no network management need
- Budget-constrained deployments
- Environments where monitoring is handled at the UPS level
| Model | Input | Outlets | Form Factor | Price Range |
|---|---|---|---|---|
| AP7540 | 200-240V 12A | 16x C13 + 4x C19 | 0U Vertical | $120-180 |
| AP7540B | 200-240V 12A | 16x C13 + 4x C19 | 0U Vertical | $130-190 |
| AP9559 | 120V 15A | 14x 5-15R | 1U Horizontal | $80-130 |
Metered Rack PDU (AP88xx Series)
Metered PDUs add real-time power monitoring. An LCD screen on the unit shows per-bank current draw. Many models also include an Ethernet port for SNMP monitoring, web interface access, and integration with data center infrastructure management (DCIM) tools.
When to use metered PDUs:
- Production server rooms (4+ devices per rack)
- Environments requiring capacity planning data
- Compliance-driven deployments (SOC 2, PCI-DSS)
- When you want to know per-outlet or per-bank power consumption
- Multi-tenant colocation where power billing matters
| Model | Input | Outlets | Monitoring | Price Range |
|---|---|---|---|---|
| AP8841 | 200-240V 30A | 42x C13/C19 | Per-bank + network | $850-1,000 |
| AP8853 | 200-240V 32A | 36x C13 + 6x C19 | Per-outlet + network | $1,100-1,400 |
| AP8886 | 200-240V 60A | 48x C13 + 12x C19 | Per-outlet + network | $1,800-2,200 |
| AP8858 | 200-240V 16A | 20x C13 + 4x C19 | Per-bank + network | $600-800 |
Switched Rack PDU (AP79xx Series)
Switched PDUs have everything metered PDUs offer, plus remote outlet-level on/off control. Via a web interface, SNMP, or CLI, you can power cycle individual outlets from anywhere on your network. This is a game-changer for remote site management.
When to use switched PDUs:
- Remote or unmanned sites (branch offices, edge deployments)
- Colocation environments where physical access is limited
- Any rack where you might need to remotely reboot a hung server or switch
- Test/lab environments where frequent power cycling is needed
| Model | Input | Outlets | Control | Price Range |
|---|---|---|---|---|
| AP7922B | 200-240V 16A | 24x C13 | Per-outlet on/off | $700-900 |
| AP7932B | 200-240V 32A | 24x C13 + 4x C19 | Per-outlet on/off | $1,000-1,300 |
| AP7941B | 200-240V 30A | 24x C13 + 12x C19 | Per-outlet on/off | $1,200-1,500 |
| AP7953B | 200-240V 32A | 42x C13 + 6x C19 | Per-outlet on/off | $1,500-1,800 |
Per-Bank vs Per-Outlet Monitoring
Metered PDUs come in two monitoring levels:
Per-bank monitoring divides outlets into groups (banks) of 6-8 outlets. You can see the total current draw for each bank but not individual outlets. This is sufficient for most server rooms where you just need to ensure you are not overloading a circuit.
Per-outlet monitoring shows the exact power draw of every single outlet. This is essential for accurate chargeback in multi-tenant environments, identifying power-hungry devices, and precise capacity planning. Per-outlet metered PDUs cost 20-30% more than per-bank models.
C13 vs C19 Outlets: What Is The Difference?
APC rack PDUs use IEC 60320 connector standards:
- C13 outlets (paired with C14 plugs) handle up to 10A (2,400W at 240V). Used by servers, switches, storage arrays, and most IT equipment.
- C19 outlets (paired with C20 plugs) handle up to 16A (3,840W at 240V). Used by high-power devices: blade enclosures, UPS units, and high-density servers with dual PSU drawing over 10A.
Rule of thumb: You need at least 2-4 C19 outlets per PDU for UPS connections and blade chassis. Everything else uses C13.
Vertical (0U) vs Horizontal (1U) Mount
- 0U Vertical: Mounts in the back of the rack alongside the vertical rails. Takes zero rack unit space. This is the standard for data centers and is how most APC rack PDUs are designed. Models: AP88xx, AP79xx series.
- 1U Horizontal: Mounts in a standard rack shelf position. Uses 1U of rack space. Better for shallow racks or when vertical space is limited. Models: AP95xx series.
For most deployments, 0U vertical is the right choice. You get your full 42U of rack space for equipment, and the PDU is accessible from the rear for cable management.
How to Choose the Right PDU
Decision Tree
- Do you need remote outlet control (reboot capability)? If yes, choose a Switched PDU (AP79xx series).
- Do you need power monitoring? If yes, choose a Metered PDU (AP88xx series).
- Do you need neither? Choose a Basic PDU (AP75xx series).
- How many outlets do you need? Count your devices, add 25% for growth.
- Do you need C19 outlets? If you have blade enclosures or UPS units, yes.
- What is your circuit amperage? Match the PDU input to your circuit: 16A, 20A, 30A, or 60A.
- 120V or 208-240V? Enterprise racks almost always use 208-240V for efficiency. Home labs may use 120V.
Key Takeaway: For a production server rack with 6-12 devices, the APC AP8841 metered PDU (200-240V, 30A, 42 outlets) is the best value. It provides per-bank monitoring, network connectivity, and enough outlets for a fully loaded rack at a reasonable price point around $895.
Dual PDU Deployment
Best practice is to deploy two PDUs per rack, connecting each server's dual power supplies to separate PDUs on separate circuits. This provides:
- Power redundancy — If one PDU or circuit fails, servers continue running on the other PSU
- Maintenance capability — You can service one PDU without downtime
- Load balancing — Distribute power evenly across two circuits
- Accurate monitoring — See total rack power as the sum of both PDUs
Pro Disk Network stocks the full range of APC rack PDUs from basic to switched. All models ship same-day from our US warehouse with free shipping over $150. Contact sales@prodisknetwork.com for help selecting the right PDU for your rack deployment.