Telkoor AC-3U-250

Technical Specifications Part Number: 900-3002-10xx Input Voltage: 90 to 264 V AC, auto-range, single phase Input Frequency: 47 to 63 Hz Inrush Current: 50 A maximum at 230 V AC Power Factor: 0.98 typical at 230 V AC full load; 0.98 typical at 115 V AC full load Efficiency: greater than 80% typical at 230 V AC full load; greater than 76% typical at 120 V AC full load Input Protection: internal IEC-type line fuse, 6.3 A 250 V AC quick-acting Brown-Out: 75 to 300 V AC for 50 ms

Output Voltages and Currents:

• V1 +5 V: adjustment range 4.8 to 5.4 V, 25 A, min load 0 A
• V2 +3.3 V: adjustment range 3.1 to 3.5 V, 36 A, min load 0 A
• V3 +12 V: 5 A, min load 0 A
• V4 -12 V: 0.5 A, min load 0 A Maximum combined output power: 250 W with 250 LFM forced air cooling

Line Regulation: ±0.5% Load Regulation: ±1% for V1 and V2; ±4% for V3 and V4 Ripple and Noise (20 MHz bandwidth, 1 µF ceramic + 120 µF electrolytic): 75 mV p-p for V1 and V2; 120 mV p-p for V3 and V4 Overload and Short Circuit Protection: fully protected, automatic recovery, 150% maximum for V1 and V2 Initial Set Point Tolerance: ±1% Overshoot and Undershoot: 0% at turn-on Hold-Up Time: 14 ms typical at full load and 220 V AC input Turn-On Delay: 2 s maximum Rise Time: 30 ms from 10% to 90% of final value Over-Voltage Protection: 110% to 130% with latched shutdown (V1, V2, V3) Temperature Protection: system shutdown on excessive internal temperature, automatic reset

Monitoring and Control:

• Remote Sense: available on V1 and V2, maximum 200 mV cable compensation
• Inhibit (INH#): TTL-compatible, low = off
• Enable (EN#): contact closure to ground on shortest pin (last-make, first-break)
• Power Fail (FAL#): TTL open-collector active low, outputs below 90%
• Current Share: single-wire on V1 and V2, ±10% accuracy, up to 6 parallel units, 50% to 100% load
• Hot Swap: internal O-ring diode
• Over-Temperature Warning (DEG#): open-collector active low, 10 °C before shutdown
• I²C (optional): passive data, serial number, model, revision, user data

Status Indicator: single bi-color LED (green = output in range; red = one or more outputs below 10%)

Environmental:

• Operating Temperature: -20 to +55 °C full load with 250 LFM forced air; derate linearly 2.5% per °C above +55 °C
• Storage Temperature: -40 to +85 °C
• Humidity: up to 95% RH non-condensing
• Shock: 20 G peak maximum
• Vibration: random 10 Hz to 500 Hz, 3-axis, 1.9 G RMS maximum
• Altitude: operation 6000 ft; non-operation 40,000 ft
• MTBF: 300,000 hours per Bellcore TR-332 at 30 °C

Regulatory and EMC:

• PICMG 2.11 CompactPCI compliance
• Safety: UL 60950, EN 60950, CE Mark
• Harmonics: EN 61000-3-2
• ESD: EN 61000-4-2 Level 4, 8 kV air
• Surge: EN 61000-4-5 Level 3, 1 kV line-to-line, 2 kV line-to-chassis
• Radiated Susceptibility: EN 61000-4-3 Level 3, 10 V/m
• EFT/Burst: EN 61000-4-4 Level 3, ±2 kV
• Conducted Disturbance: EN 61000-4-6 Level 2, 3 V RMS
• Emissions: EN 55022/CISPR 22 Class B with external line filter
• Dielectric Withstand: input-to-case 1500 V AC; input-to-output 3000 V AC; output-to-case 100 V DC

Mechanical:

• Dimensions: 128.7 mm × 40.6 mm × 162.5 mm (5.07 in × 1.60 in × 6.40 in)
• Weight: 800 g
• Connector: Positronic PCIH47M400A1/AA 47-pin

Functional Features Universal auto-range 90 to 264 V AC input accepts worldwide mains without configuration. Active power factor correction achieves 0.98 PF across full load. Four regulated DC outputs cover standard CompactPCI voltage requirements. Hot-swap capability with internal O-ring diode supports live insertion and removal. Current sharing enables up to six units to operate in parallel for N+1 redundancy. Remote sense on +5 V and +3.3 V compensates for cable voltage drops. I²C bus reports serial number, model, revision, and user data to a system manager. Bi-color front-panel LED provides immediate health status.

Application Scenarios CompactPCI industrial PCs, telecom central-office equipment, military COTS systems, railway signaling computers, test and measurement instrumentation, industrial automation controllers, and embedded computing chassis requiring 3U form-factor AC-input power with PICMG 2.11 compliance and N+1 redundancy.

Performance Parameters Total output power: 250 W at 250 LFM cooling Peak current: +5 V 25 A, +3.3 V 36 A Hold-up time: 14 ms at full load / 220 V AC Turn-on delay: ≤ 2 s Rise time: 30 ms MTBF: 300,000 hours at 30 °C Efficiency: >80% at 230 V AC full load Power factor: 0.98

Material Composition Steel chassis with zinc-plated or chromate conversion finish. Aluminum heat sinks and cooling duct. FR-4 glass-epoxy PCB with through-hole and surface-mount components. Aluminum electrolytic bulk capacitors. Toroidal and planar transformers. Positronic 47-pin connector with gold-plated contacts. Plastic front bezel with bi-color LED light pipe.

Structural Features 3U-height (128.7 mm) × 40.6 mm wide × 162.5 mm deep plug-in power module. Front bezel houses a bi-color status LED and forced-air cooling vents. Rear 47-pin Positronic connector mates with the CompactPCI backplane. Internal layout includes an input EMI filter stage, PFC boost converter, main DC-DC converter stage, output rectification and filtering, and a secondary control/monitoring board. Cooling airflow enters from the front and exits through the rear/side.

Working Principle AC input passes through an EMI filter and a PFC boost converter that shapes the input current to match the voltage waveform, achieving near-unity power factor and generating a regulated 380 to 400 V DC bus. A phase-shifted full-bridge or resonant DC-DC converter steps down the high-voltage bus to intermediate voltages. Secondary synchronous rectifiers and LC filters produce the four regulated DC outputs. A digital or analog PWM controller regulates output voltage, provides over-voltage and over-current protection, and manages the power-fail and inhibit signals. The hold-up capacitor stores enough energy to maintain outputs for 14 ms after input loss.

Installation Requirements Insert the module into a CompactPCI 3U power supply slot in a PICMG 2.11-compliant chassis. Ensure the 47-pin Positronic connector aligns with the backplane and the injector/ejector handle locks into place. Connect AC input through the chassis backplane or dedicated AC input connector. Verify forced-air cooling provides at least 250 LFM airflow across the module. For parallel operation, connect the current-share pin on all units and configure one unit as the master. Ensure input AC wiring uses the correct gauge for the input current.

Usage Precautions Do not operate without sufficient forced-air cooling; the unit requires 250 LFM to deliver full 250 W. Derate output power by 2.5% per degree Celsius above +55 °C. Do not block the front or rear airflow vents. When hot-swapping, use the injector/ejector handle to control insertion speed and prevent backplane damage. For parallel current sharing, use identical model units and connect the share bus. Do not open the unit; it contains hazardous high-voltage capacitors that retain charge after removal. Verify AC input voltage is within 90 to 264 V AC before energizing. Replace the internal fuse only with the specified IEC-type 6.3 A 250 V AC quick-acting fuse.