Protection Features
| OCP (Normal @ 28.7°C) | 12V: 65.60A (121.48%), 12.062V 5V: 25A (138.89%), 5.062V 3.3V: 24.9A (138.33%), 3.299V 5VSB: 3.6A (144.00%), 4.937V |
| OCP (Hot @ 43.1°C) | 12V: 63.20A (117.04%), 12.061V 5V: 25.2A (140.00%), 5.063V 3.3V: 24.9A (138.33%), 3.299V 5VSB: 3.6A (144.00%), 4.924V |
| OPP (Normal @ 28.2°C) | 876.66W (134.87%) |
| OPP (Hot @ 43.4°C) | 832.32W (128.05%) |
| OTP | ✓ (140°C @ Secondary Side) |
| SCP | 12V to Earth: ✓ 5V to Earth: ✓ 3.3V to Earth: ✓ 5VSB to Earth: ✓ -12V to Earth: ✓ |
| PWR_OK | Proper Operation |
| UVP (Full Load @ 90V) | ✓ |
| UVP (No Damage @ 80V) | ✓ |
| Conducted Emissions EN55032 & CISPR 32A | ✗ |
| NLO | ✓ |
| Fan Failure Protection | ✗ |
| SIP | Surge: MOV Inrush: NTC & Bypass Relay |
The 12V rail’s OCP triggering points are set conservatively, and there is a satisfactory difference between normal and hot modes. On the other hand, the OCP triggering points are set high on the minor rails, and to make things worse, the triggering points are identical between normal and hot conditions. This is not good because the PSU is stressed way more under high operating conditions.
The over power protection is set correctly, and all other essential protection features, except for fan failure, are present.
EMC Pre-Compliance at a Glance
Every electronics device, including PSUs, can be an EMI source, which, depending on the amount of EMI emitted, can affect the proper operation of nearby devices. EMI can, in some extreme cases, even render them unusable. Some standards have been established to minimize electromagnetic interference (EMI) noise. The corresponding standards for IT (Information Technology) products are CISPR 32 and its derivative, EN 55032, which applies to products sold in the EU. In the EU, every product bearing the “CE” marking must comply with the EN 55032 standard. CISPR 32 and EN 55032 standards categorize devices into two classes: A and B. Class B equipment is intended for domestic environments. Hence, its permitted EMI emissions are significantly lower than those of A-class devices.
Our equipment for EMI readings:
- Rohde & Schwarz FPC1500 (loaded with all options)
- Tekbox TBLC08 LISN
- Tekbox TBFL1 transient limiter
- Tekbox EMCview software
| CISPR 32 / EN55032 Limits | ||
| CISRP 32 / EN 55032 Class A Conducted EMI Limit | ||
| Frequency of Emission (MHz) | Conducted Limit (dBuV) | |
| Quasi-peak | Average | |
| 0.15 – 0.50 | 79 | 66 |
| 0.50 – 30.0 | 73 | 60 |
| CISPR 32 / EN 55032 Class B Conducted EMI Limit | ||
| Frequency of Emission (MHz) | Conducted Limit (dBuV) | |
| Quasi-peak | Average | |
| 0.15 – 0.50 | 66 – 56 | 56 – 46 |
| 0.50 – 5.00 | 56 | 46 |
| 5.00 – 30.00 | 60 | 50 |
| CISRP 32 / EN 55032 Class A 10-Meter Radiated EMI Limit | ||
| Frequency of Emission (MHz) | Field Strength Limit (dBuV/m) | |
| 30 – 88 | 39 | |
| 88 – 216 | 43.5 | |
| 216 – 960 | 46.5 | |
| > 960 | 49.5 | |
| CISRP 32 / EN 55032 Class B 3-Meter Radiated EMI Limit | ||
| Frequency of Emission (MHz) | Field Strength Limit (dBuV/m) | |
| 30 – 88 | 40 | |
| 88 – 216 | 43.5 | |
| 216 – 960 | 46.0 | |
| > 960 | 54.0 | |
Please note that the ATX spec allows a 4 dB margin for conducted and radiated emissions. This means that if a PSU exceeds the limits but stays within the 4 dB margin, it meets the corresponding ATX spec requirement (8.1 Emissions).
EMI Results
In the samples I got, conducted EMI emissions were extremely high at low frequencies. The transient filter needs fixing ASAP. Note that the 750W model, which uses the same platform, also yielded similar results.
