531X302DCIBAG3 | GE 302 Series Mainframe Chassis

Description

Product Introduction

The 302 series is GE’s heavy-duty DC-powered chassis, and the BG3 combines dual redundant 300W power modules with the B-type DC input filter—providing 80dB of attenuation at 150kHz and 20kA surge protection. It’s the ultimate chassis for critical applications in high-noise environments: steel mills, mining operations, and large DC bus systems with heavy welding equipment or frequent lightning strikes.

The model number is descriptive: “302” is the high-power DC chassis, “DCI” indicates DC input with isolation, “B” indicates the dual bay configuration, “A” is the standard A-type filter, and “G3″ is the revision with the 80mm fans and the B-filter. The B-type filter is physically larger and adds about 1″ to the chassis depth. The chassis has two power supply bays, each accepting a 300W DC-DC converter (531X302PWR1). The outputs are diode-ORed on the backplane—failover is automatic and seamless (<100ms). The depth is 19.5” to accommodate the dual modules and the B-filter. The fans are 80mm (45 CFM). One caveat: the B-filter has a higher leakage current (about 3mA) than the A-type (1.5mA), which could trip sensitive GFCIs.

Key Technical Specifications

Compatible Replacement Models

✅ Drop-in Replacement:

• 531X302DCIBAG3 directly replaces 531X302DCIBAG2 and 531X302DCIBAG1. The BG3 has the same redundant architecture, same dual bays, same diode-OR backplane. The only difference is the fans—the BG3 has 80mm fans (same as the BG1). The BG3 revision improved the fan bearings. Swap your boards and power modules over.
• 531X302DCIBAG1 (A-filter version): The BG3 is the B-filter version of the BG1. If you need enhanced surge protection, the BG3 is a direct replacement. The backplane and slot spacing are identical.

⚠️ Software Compatible (Requires Recompile):

• None. The redundant power system is purely hardware—diode-OR, status monitoring, and LED indicators. No firmware, no configuration. No recompile needed.

❌ Hardware Incompatible:

• 531X302DCIBAG3 with mismatched power modules: Both modules must be identical (both 531X302PWR1). Mixing modules can cause voltage regulation issues.
• 531X302DCIBAG3 with a DC bus that has high leakage current: The B-filter’s leakage current is 3mA per module (6mA total). If your DC bus already has leakage from other equipment, you might trip GFCIs. Check your installation.
• 531X302DCIBAG3 with a master chassis that doesn’t support expansion: The 302 can be a master or expansion chassis. If using it as an expansion, the master must support the 302 interface.
• 531X302DCIBAG3 with a 212-series AC power supply: The 302 is DC input only.

Frequently Asked Questions (FAQ)

Q: What’s the difference between the BG3 and the BG1?

A: The filter. The BG3 has the B-type filter (80dB attenuation, 20kA surge), while the BG1 has the A-type filter (60dB, 5kA). The B-filter is larger and adds 1″ to the chassis depth. The BG3 is recommended for environments with frequent lightning strikes or heavy welding equipment on the same DC bus.

Q: Does the B-filter cause GFCI issues?

A: Yes, it can. The B-filter has a leakage current of about 3mA per module. With two modules, the total leakage is about 6mA. A typical GFCI trips at 5mA. Use a GFCI with a higher threshold (10mA or 30mA) or a non-GFCI circuit. Check local electrical codes.

Q: Can I replace a power module while the chassis is running?

A: Yes. The power modules are hot-swappable. You can pull out a failed module and slide in a new one without powering down the chassis. The other module will keep the backplane powered. However, be careful: the module you’re removing might be hot. We recommend powering down for safety, but the BG3 supports hot-swap.

Q: What’s the total power capacity of the BG3?

A: The total power capacity is 300W—the same as a single module. The redundancy doesn’t increase capacity. Both modules share the load when both are working (they’re load-balanced), but the total is still 300W. If one module fails, the other module takes the full 300W load.

Q: Does the BG3 require the same power module model in both bays?

A: Yes. Both modules must be identical (both 531X302PWR1). Mixing models can cause voltage regulation issues—one module may try to drive the other, leading to overheating or failure. If you’re upgrading, buy two identical modules.

Q: The BG3 has 80mm fans. Is that enough for 300W with two modules and the B-filter?

A: Yes. The B-filter adds about 5W of heat per module, and the two modules share the load. The 80mm fans (45 CFM) are sufficient. The chassis runs about 4°C warmer than the single-power 302, which is within spec.

Q: Does the BG3 have a separate DC input for each module?

A: Yes. Each power module has its own DC input terminal. You should power each module from a separate DC source (e.g., two separate battery banks or two separate UPS outputs) for true redundancy. If both modules are on the same DC bus, a single bus failure could take out both. We recommend separate sources.

Q: The BG3 is 42 lbs empty. Is that a problem for rack mounting?

A: The BG3 is the heaviest of all 302-series chassis—use all four mounting screws on each rack ear. For high-vibration environments, we recommend support rails under the chassis. Ensure your rack rails are rated for at least 60 lbs per chassis.

Q: Does the BG3 come with the expansion cable?

A: No. The expansion cable (fiber-optic or backplane ribbon) is not included. The BG3 has the ports for the cable, but you need to supply the cable separately. We recommend using the GE-supplied cable.

Q: Can I use the BG3 with a 24V DC input?

A: Yes. Each power module accepts 24V, 48V, or 125V DC, jumper-selectable. Set both modules to the same input voltage. At 24V input, each module draws up to 15A at full load—so ensure your DC bus can provide the required current.

Q: What’s the relay rating on the status output?

A: The dry contact relay is rated for 2A @ 30V DC or 0.5A @ 120V AC. It’s a Form A contact (NO). The relay is energized when both modules are OK. If one module fails, the relay de-energizes. You can wire this to a PLC input, an alarm lamp, or a safety relay.

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