Vertiv Rpdu Monitored Unit Level EC 20A 208V 3.3KW Horizontal (10) Locking IEC C1 - VP4N21A2

Vertiv VP4N21A2 Monitored Horizontal Rack PDU — 20A, 208V, 10-Outlet

Overview

The Vertiv VP4N21A2 is a single-phase, unit-level monitored rack PDU rated at 20A and 208V (3.3kW) with ten locking IEC C13 outlets — purpose-built for horizontal 0U rack deployment in data centers and server rooms where outlet-level visibility and remote power management matter. Feeding off a NEMA L6-20P plug and delivering current, voltage, and power monitoring over a full enterprise protocol stack, the VP4N21A2 gives operations teams the telemetry they need to avoid overloads and document capacity in real time. The 3-meter input cable provides enough reach to span most rack-to-PDU-distribution distances without patch extensions.

Key Features

• Unit-Level Monitoring (Current, Voltage, Power): The VP4N21A2 tracks aggregate current draw, input voltage, and real power at the PDU level — displayed locally on the built-in LCD and streamed remotely. For capacity planning teams, this means you can identify branches trending toward 80% load threshold without physically pulling a clamp meter on every circuit.
• 10 Locking IEC C13 Outlets: Locking connectors prevent accidental disconnection from cable sag or incidental contact — a real concern in dense 1U server populations where PDU outlets are at arm's reach constantly. The C13 format is compatible with the vast majority of 1U and 2U server power supplies and network gear power cords.
• NEMA L6-20P Input Plug — 20A at 200–240V: The L6-20P twist-lock plug pairs with standard 20A 208V circuits common in raised-floor and overhead busway environments. Operating across the 200–240V range (50/60 Hz) means this PDU travels well across North American 208V three-phase distributions and European 230V single-phase feeds without any hardware change.
• Horizontal 0U Mounting: Zero-U horizontal form factor fits in a standard 1U rack space, keeping all ten outlets facing the rear of the rack for clean, cable-managed installations. It does not consume vertical rack units otherwise assigned to active equipment.
• Enterprise Protocol Stack — SNMP v1/v2c/v3, HTTPS, SSH, LDAP, RADIUS, TACACS+: SNMP v3 with authentication and encryption means monitoring integrates cleanly with enterprise NMS platforms (SolarWinds, PRTG, Nagios, Zabbix) without exposing clear-text credentials. RADIUS and TACACS+ support lets you roll PDU access into your existing AAA infrastructure rather than managing local usernames on every device. LDAP ties authentication to your directory.
• IPv4 and IPv6 Dual-Stack: Modern data centers running dual-stack networks can address this PDU natively on IPv6 without a NAT workaround — a minor but meaningful point as more colocation and enterprise environments accelerate their v6 deployments.
• Modbus TCP Support: For facilities teams running building management systems (BMS) or DCIM platforms that speak Modbus TCP, the VP4N21A2 exposes its monitoring data natively — eliminating the need for protocol translators or custom integrations.
• RJ-45 Network Port + USB + Serial (DB9): Single RJ-45 for network management; USB and serial ports for local console access and firmware operations — the serial port is especially useful for out-of-band access when network connectivity is disrupted during incident response.
• LCD Display: Local LCD readout means technicians can read current draw without a laptop or network access — relevant during initial commissioning or when troubleshooting a suspected overload condition physically at the rack.
• RSTP Network Protocol: Rapid Spanning Tree Protocol support prevents network loops in environments where management network redundancy is configured — keeps the PDU's management interface online even during switch failover events.
• Syslog + SMTP Alerting: Syslog output integrates with any SIEM or log aggregation platform; SMTP enables direct email alerting on threshold breaches without requiring an external agent or middleware.

Integration and Compatibility

The VP4N21A2 connects to any rack power distribution management environment supporting SNMP, Modbus TCP, or HTTP/HTTPS-based interfaces. Its dual-stack IP support and full AAA protocol coverage (RADIUS, TACACS+, LDAP) make it straightforward to incorporate into enterprise data center fabrics already running structured Vertiv power infrastructure. DCIM platforms with native Modbus TCP drivers can poll this PDU directly for real-time capacity data. Pair with upstream UPS and power conditioning equipment on the same 20A 208V circuit to build a complete monitored power path from utility input to server inlet. For teams managing multiple racks, the SNMP v3 interface plugs into existing network management workflows without additional licensing overhead.

Frequently Asked Questions

Q: What input plug does the VP4N21A2 use, and what circuit does it require?

A: The VP4N21A2 uses a NEMA L6-20P twist-lock plug and requires a 20A, 200–240V single-phase circuit (50/60 Hz). In North American data centers, this is typically a 208V 20A dedicated circuit from a PDU distribution panel or busway tap.

Q: Does the VP4N21A2 support SNMP v3?

A: Yes. The VP4N21A2 supports SNMP v1, v2c, and v3. SNMP v3 provides authentication and encryption, making it compatible with enterprise NMS environments that require secure polling without clear-text community strings.

Q: Can the VP4N21A2 integrate with RADIUS or TACACS+ for user authentication?

A: Yes. Both RADIUS and TACACS+ are supported network protocols on this PDU, allowing you to manage access credentials through your existing AAA infrastructure rather than maintaining local accounts on each device.

Q: What does 'unit-level monitored' mean for the VP4N21A2?

A: Unit-level monitoring means the PDU tracks and reports aggregate current, voltage, and power at the PDU input — not at each individual outlet. You can see total load on this PDU, but outlet-by-outlet switching or per-outlet metering requires a switched or outlet-monitored PDU model.

Q: Does the VP4N21A2 support Modbus TCP?

A: Yes. Modbus TCP is included in the supported protocol list, which allows direct integration with DCIM platforms and building management systems that use Modbus as their native communication protocol.

Q: How many rack units does the VP4N21A2 occupy?

A: The VP4N21A2 is a 0U horizontal PDU, meaning it mounts in a standard 1U rack space but its classification as 0U reflects that it is designed for the rear of the rack and does not consume vertical rack space intended for servers or active equipment.

Karl Wilson

The VP4N21A2 hits a specific deployment sweet spot: you want real-time power telemetry and enterprise AAA integration on a 208V 20A circuit, but you don't need per-outlet switching or individual outlet metering. The unit-level monitoring at 20A/3.3kW with SNMP v3 and Modbus TCP gives operations teams meaningful capacity data without paying for outlet-switched functionality most 1U server racks don't actually require.

Technical Highlights:

• 10 Locking IEC C13 Outlets: Locking connectors on all ten C13 positions are worth more than they look on a spec sheet — in dense rear-of-rack installs where cables get pulled regularly, non-locking outlets become a reliability liability. The VP4N21A2 closes that gap at the unit-monitored tier.
• Full AAA Protocol Stack: RADIUS + TACACS+ + LDAP means this PDU integrates with enterprise identity management on day one. No local credential spreadsheets, no one-off password resets — your standard onboarding/offboarding flow covers it.
• Modbus TCP + SNMP v3: Dual-protocol monitoring output means this unit feeds both traditional NMS tools (via SNMP v3 with encrypted polling) and DCIM or BMS platforms that speak Modbus natively — no protocol bridge hardware required.

Deployment Considerations:

• The 3-meter input cable covers most rack-to-overhead-busway distances, but verify your specific floor PDU or busway tap location before ordering — unusually deep racks or offset busway positions may require a cable extension or repositioning the distribution point.
• Unit-level monitoring is aggregate only. If your runbook requires per-outlet current tracking for individual server chargeback or fault isolation, step up to an outlet-monitored variant in the Vertiv lineup — the VP4N21A2 won't give you that granularity.

Best fit for colocation environments, enterprise server rooms, and edge deployments where a 208V 20A circuit feeds a mixed 1U/2U server population and the operations team needs SNMP-polled power data integrated into an existing NMS — without the cost or complexity of a fully switched PDU.