Siemens ep3337-8sb00-0ay0

By Abdullah Zahid
12 min read
Siemens 6EP3337-8SB00-0AY0 SITOP PSU8200 24V 40A DIN rail power supply for industrial control cabinets

Siemens 6EP3337-8SB00-0AY0 SITOP PSU8200 24 V/40 A Stabilized Power Supply — Specs, Selection Guide, and Where to Buy

Controls engineers specifying a 24 V DC rail for a SIMATIC-based control cabinet are typically at one of two decision points: confirming the 6EP3337-8SB00-0AY0 is the correct part number before submitting a purchase order, or validating that 40 A continuous output at 960 W is enough headroom for a growing sensor and I/O load. The Siemens 6EP3337-8SB00-0AY0 is a single-phase switched-mode DIN rail power supply in the SITOP PSU8200 family, converting 120/230 V AC input to regulated 24 V DC at 40 A, with an MTBF of 838,156 hours at 40°C and a global certification portfolio covering UL, CSA, CE, EAC, RCM, and BIS. If those numbers already match your BOM, the next step is straightforward.

If you have already confirmed this is the correct part, check current pricing and availability for the 6EP3337-8SB00-0AY0 at LeadTime.ca — ships worldwide.

Does the Siemens 6EP3337-8SB00-0AY0 Fit Your Project Requirements?

This model is the right choice when all of the following are true for your installation:

  • Your input supply is single-phase 120 V or 230 V AC — the operating range covers 170 to 264 V AC at 45 to 65 Hz line frequency
  • Your total control circuit load does not exceed 40 A continuous (960 W output capacity)
  • You are mounting to a standard 35 mm DIN rail with 135 mm of horizontal space and 40 mm clearance above and below
  • Your load requires regulated 24 V DC — not 12 V, 5 V, or any other output voltage
  • A 25 ms holdup time on mains loss is acceptable for your control stability requirement — if uninterruptible supply is needed, a separate buffer module is required
  • UL, CSA, or CE certification is required for your installation jurisdiction

If your facility runs three-phase 400 V AC input or your load exceeds 40 A, this is not the correct model. The 6EP3437-8SB00-0AY0 supports 50 A output and three-phase input. If your budget requires a lower-current variant, the 6EP3436-8SB00-0AY0 covers the 20 A application at reduced cost.

On this page:

What the SITOP PSU8200 24 V/40 A Actually Does in a Control Cabinet

The 6EP3337-8SB00-0AY0 is not a generic power brick — it is a stabilized switched-mode supply designed to serve as the regulated 24 V DC backbone of an industrial control panel. Its primary role is converting single-phase 120/230 V AC mains into clean, regulated 24 V DC at up to 40 A continuous to feed SIMATIC PLC logic, distributed I/O modules, sensor networks, safety relays, and solenoid valves from a single DIN rail-mounted source.

What distinguishes it from commodity supplies is the combination of a 2 ms load step response and 1 ms settling time, which matters in applications where solenoid coils release or PLC scan cycles generate sudden current transients. The 25 ms holdup time provides a brief ride-through buffer on mains dips — enough to prevent nuisance shutdowns during minor utility interruptions without requiring a battery system. The ±3% output voltage tolerance and 50 mV typical ripple keep downstream logic devices and sensors operating within their specified input windows. Short-circuit protection operates via a constant current characteristic at approximately 41 A, with an optional latching shutdown mode signaled through auxiliary terminals 13 and 14 to a PLC input or safety relay.

The 838,156-hour MTBF at 40°C operating temperature is not a theoretical ceiling — it reflects the field reliability standard the SITOP family is specified against in safety-critical automotive and pharmaceutical installations where unplanned downtime carries hard cost consequences.

Typical System Architecture for the 6EP3337-8SB00-0AY0

The 6EP3337-8SB00-0AY0 sits at the power conversion layer of the control cabinet — between the facility's single-phase AC supply and every 24 V DC device downstream. Here is the typical component chain:

  • Facility single-phase 120/230 V AC supply feeds through main disconnect and branch circuit protection to the power supply input terminals (L, N, PE, screw terminals 0.2–4 mm²)
  • The 6EP3337-8SB00-0AY0 converts and regulates to 24 V DC at the output terminals (0.5–10 mm²), providing up to 40 A continuous to the downstream 24 V rail
  • SIMATIC PLC CPU and distributed I/O modules (ET 200 series or similar) draw logic and field power from the regulated 24 V rail
  • Sensors, proximity switches, solenoid valves, and safety relays connect to the same 24 V bus via terminal blocks or marshalling racks within the cabinet
  • Optional buffer module (6EP3354-2SB00, sold separately) can be inserted between the power supply output and the 24 V bus to extend holdup time beyond the standard 25 ms for uninterruptible control duty

Industries and Applications Where This Power Supply Is Specified

In discrete manufacturing and automotive assembly environments, the 6EP3337-8SB00-0AY0 serves as the primary power source for distributed I/O gateway devices and PLC sensor networks across multi-zone production lines. Its 960 W output capacity accommodates the cumulative 24 V load of dozens of sensors and I/O channels on a single supply without requiring paralleled units.

In packaging machinery and food and beverage processing, the combination of UL and CSA certification and the -25 to +70°C operating temperature range (natural convection cooling) makes it suitable for installation in both climate-controlled control rooms and less conditioned machine enclosures.

Pharmaceutical manufacturing and water treatment applications specify this model specifically because of the MTBF documentation — 838,156 hours at 40°C — which satisfies reliability requirements in validation and equipment qualification (IQ/OQ) packages without requesting special data from the manufacturer.

For panel builders performing retrofit and cabinet upgrades on legacy Siemens SIMATIC systems, the 6EP3337-8SB00-0AY0 serves as a direct 24 V DC replacement for older SITOP generation supplies, retaining screw terminal wiring compatibility and DIN rail footprint within existing cabinet layouts.

Application Typical Deployment
Discrete manufacturing production line Primary 24 V supply for distributed I/O modules and gateway devices
Automotive assembly cell Regulated supply for SIMATIC PLC, safety relays, and E-stop circuits
Packaging machinery control panel Central 24 V DC source for sensor arrays and solenoid valve banks
Pharmaceutical manufacturing equipment Validated supply with MTBF documentation for IQ/OQ packages
HVAC and building automation control cabinet Regulated 24 V bus for zone controllers and field devices
Panel retrofit / cabinet upgrade Drop-in 24 V replacement for end-of-life SITOP generation supplies

Purchase-Decision Specs at a Glance

Parameter Value
Input Voltage 120/230 V AC single-phase, 170–264 V operating range
Input Line Frequency 50/60 Hz (45–65 Hz operating window)
Output Voltage 24 V DC, ±3% tolerance
Output Current (Rated) 40 A continuous (960 W)
Holdup Time at Rated Load 25 ms minimum
Output Ripple 50 mV typical, 100 mV maximum
Load Step Response 2 ms (50–100% load change)
MTBF at 40°C 838,156 hours
Operating Temperature -25 to +70°C (natural convection cooling)
Certifications CE, UL (File E197259, cULus), CSA C22.2 No. 107.1, EAC, RCM, BIS (R-41183539), CB

Full technical specifications are available on the product page at LeadTime.ca.

6EP3337 vs. 6EP3436 vs. 6EP3437: Which SITOP PSU8200 Do You Actually Need?

Model Output Current Output Power Input Type Best For
6EP3436-8SB00-0AY0 20 A 480 W Single-phase AC Cost-sensitive installations with lower 24 V DC load budgets
6EP3337-8SB00-0AY0 (this model) 40 A 960 W Single-phase 120/230 V AC Standard industrial control cabinets with medium-to-high 24 V loads
6EP3437-8SB00-0AY0 50 A Higher capacity Three-phase 400 V AC also available High-power applications or facilities with three-phase supply only

If your cabinet load calculation lands at or below 40 A on single-phase AC, the 6EP3337-8SB00-0AY0 is the correct choice — check current stock and pricing at LeadTime.ca.

Expert Verdict: Honest Assessment Before You Commit

The 6EP3337-8SB00-0AY0 earns its place on the BOM because it does the core job without compromise: stable 24 V DC at 40 A, fast transient recovery at 2 ms, a real-world MTBF of 838,156 hours, and a certification portfolio — UL File E197259, CSA C22.2 No. 107.1, CE, EAC, RCM, and BIS R-41183539 — that covers essentially every jurisdiction where industrial controls are installed without requiring a second SKU. The 170–264 V AC operating window is wide enough that voltage sags and regional utility variation become non-issues. For a SIMATIC-based control cabinet running single-phase AC input with a 24 V DC load below 40 A, this is a low-risk, well-documented choice with an active product status and no announced end-of-life.

Where this model has real limits: the 25 ms holdup time is not a substitute for uninterruptible control power. If your application requires the 24 V rail to stay live through a multi-second mains interruption — emergency lighting, safety system memory retention, or fault logging during power loss — the 6EP3337-8SB00-0AY0 alone will not meet that requirement. A buffer module such as the 6EP3354-2SB00 is sold separately and must be specified explicitly. Similarly, if your panel feed is three-phase 400 V AC, ordering this model is a wiring mismatch — the 6EP3437 series is the correct starting point. The 40 A output also has no headroom for future load growth beyond that rated ceiling; if your load analysis shows 35–38 A today with expansion planned, moving to the 50 A variant at specification stage is the lower-risk decision.

From a procurement standpoint, the 6EP3337-8SB00-0AY0 is an active global SKU with no regional variants — one part number serves North America, Europe, and Asia-Pacific. Typical availability through stocking distributors runs 1–2 weeks; direct factory lead times have historically run 4–6 weeks. For projects with hard commissioning dates, confirming in-stock availability at time of order is the practical move. If this matches your system requirements, view current stock and pricing at LeadTime.ca.

For volume pricing or to confirm lead time before committing to a build, contact the LeadTime.ca team directly — we ship worldwide.

Wiring and Installation Overview

The following points cover the key requirements for a correct installation. Engineers requiring full wiring diagrams or commissioning procedures should reference the Siemens SITOP PSU8200 installation manual from siemens.com.

  • Input terminals accept 0.2–4 mm² wire for L (phase), N (neutral), and PE (earth) connections; verify single-phase AC availability at 120 V or 230 V before connecting
  • Output terminals accept 0.5–10 mm² wire for the 24 V DC positive (+) and negative (–) rails; for a full 40 A load, minimum 4 mm² stranded wire is recommended to control voltage drop over typical cabinet run lengths
  • Mount horizontally on a standard 35 mm DIN rail with 135 mm of clear width and a minimum 40 mm clearance above and below for natural convection airflow — no forced cooling required
  • Optional auxiliary terminals 13 and 14 accept 0.14–1.5 mm² wire to signal the latching shutdown state to a PLC digital input or safety relay; these terminals are not required for basic operation
  • After energizing, verify the green LED (24 V OK) is illuminated and measure output with a digital multimeter — expected range is 23.3 to 24.7 V DC (±3%) at no load before connecting the full system

Compatible Buffer Modules and System Expansion

The 6EP3337-8SB00-0AY0 is designed to operate within the broader SITOP PSU8200 ecosystem. The following accessory is confirmed compatible based on product family documentation:

  • 6EP3354-2SB00 Buffer Module — Optional add-on sold separately; extends holdup time beyond the standard 25 ms for applications requiring uninterruptible 24 V DC control power during mains interruptions. Must be specified separately and is not included with the power supply.

What Engineers Get Wrong When Ordering This Part

Before submitting a purchase order for the 6EP3337-8SB00-0AY0, run through this checklist. Every item on it corresponds to a real ordering or installation error that results in either a non-functional installation or a return shipment.

  1. Verify input voltage phase: this model accepts SINGLE-phase 120/230 V AC only (not 3-phase)
  2. Confirm output current requirement: 40 A continuous maximum (not 20 A or 50 A models)
  3. Check DIN rail availability in cabinet (standard 35 mm rail, 135 mm width required)
  4. Verify regulated 24 V DC output is required (not 12 V, 5 V, or higher voltages)
  5. Confirm no SFP requirement: this model has 25 ms holdup time (battery backup modules sold separately)
  6. Check installation environment: rated -25 to +70°C operating, natural convection cooling only
  7. Verify load characteristics: resistive loads primarily, short-circuit protected but requires monitoring

If any item on this checklist raises a flag, contact the LeadTime.ca team before ordering — we can confirm the correct variant and check availability worldwide.

Frequently Asked Questions

Can the 6EP3337-8SB00-0AY0 operate on both 120 V and 230 V AC without rewiring or jumper changes?

Yes. The operating voltage range of 170–264 V AC covers both nominal 120 V and 230 V single-phase supplies within their normal utility tolerance bands. No internal switching, jumper, or wiring change is required when moving between regions or supply voltages within that range. Confirm your facility supply falls within 170–264 V AC before installation.

Is 25 ms holdup time sufficient for a SIMATIC PLC to complete a safe shutdown on mains loss?

For most SIMATIC CPU models, 25 ms is sufficient to execute a controlled program stop and retain data in retentive memory — but this depends on your specific CPU model, program cycle time, and whether field devices also require live power during shutdown. If your safety analysis requires longer ride-through, the 6EP3354-2SB00 buffer module is the correct addition and must be specified separately.

Does the 6EP3337-8SB00-0AY0 require forced air cooling or a fan?

No. The unit is rated for natural convection cooling only across its full operating range of -25 to +70°C. The 40 mm minimum clearance above and below the unit is required to maintain adequate airflow. Do not block this clearance with cable ducts or adjacent components. No fan or forced ventilation is needed or recommended.

What certifications are required for North American installation and does this model qualify?

North American industrial panel installations typically require UL Listing and CSA certification for acceptance by the authority having jurisdiction (AHJ). The 6EP3337-8SB00-0AY0 carries cULus Listing under UL File E197259 and CSA C22.2 No. 107.1, satisfying both requirements. Request the Declaration of Conformity and UL certification documentation from your distributor at time of order for inclusion in inspection records.

What is the short-circuit behavior and does the unit auto-recover?

Under short-circuit conditions, the 6EP3337-8SB00-0AY0 responds with a constant current characteristic at approximately 41 A before entering either current limiting or latching shutdown mode. The latching shutdown condition is signaled via auxiliary terminals 13 and 14. Recovery from latching shutdown requires clearing the fault and cycling input power — it does not auto-restart. This behavior is intentional for applications where an unmonitored restart after a fault would be a safety concern.

Is the 6EP3337-8SB00-0AY0 an active product or is it approaching end-of-life?

As of the current research date, the 6EP3337-8SB00-0AY0 carries Active Product status with no end-of-life announcement from Siemens. It is a standard stocking item at major authorized distributors globally. For the most current product lifecycle status, confirm with your distributor at time of order — product status can change without advance notice in industrial automation lines.

Why Order the 6EP3337-8SB00-0AY0 From LeadTime.ca

  • Ships worldwide — not restricted to any single country or region
  • Sourcing support for hard-to-find or short-lead-time Siemens SITOP parts across the PSU8200 family
  • Volume pricing available — contact the team directly for BOM-level or multi-unit orders
  • Fast response for lead time confirmation before project commitment — no waiting days for a quote
  • Certification documentation (UL, CSA, CE) available to support panel inspection packages

At-a-Glance Summary

  • Model: Siemens 6EP3337-8SB00-0AY0 — SITOP PSU8200 24 V/40 A Stabilized Power Supply
  • Input: Single-phase 120/230 V AC, 170–264 V operating range, 45–65 Hz
  • Output: 24 V DC at 40 A continuous, 960 W rated capacity
  • Output ripple: 50 mV typical, 100 mV maximum
  • Load step response: 2 ms (50–100% load change); settling time 1 ms
  • Holdup time: 25 ms minimum at rated current — buffer module sold separately for extended ride-through
  • Short-circuit characteristic: approximately 41 A constant current with latching shutdown option via terminals 13 and 14
  • MTBF: 838,156 hours at 40°C operating temperature
  • Operating temperature: -25 to +70°C, natural convection cooling only
  • Enclosure: 135 x 145 x 150 mm, 35 mm DIN rail mount, 40 mm top/bottom clearance required
  • Net weight: 6.6 lb (approximately 3 kg)
  • Certifications: CE, UL File E197259 (cULus), CSA C22.2 No. 107.1, EAC, RCM, BIS R-41183539, CB
  • Product status: Active — no end-of-life announced as of current research date
  • Related variants: 6EP3436-8SB00-0AY0 (20 A), 6EP3437-8SB00-0AY0 (50 A, three-phase input available)