Protection Features
| OCP (Cold @ 30°C) | – |
| OCP (Hot @ 41°C) | – |
| OPP (Cold @ 29°C) | – |
| OPP (Hot @ 42°C) | – |
| OTP | – |
| SCP | – |
| PWR_OK | – |
| NLO | ✓ |
| Fan Failure Protection | ✗ |
| SIP | Surge: MOV Inrush: NTC & Bypass Relay |
This table is empty because during the turn-on transient response test, where we apply a full load, we noticed that the PSU’s EPS cable started to deliver spirit. Apparently, this situation originated from the previous testing, which involved high loads under high temperatures. In any case, this didn’t allow us to continue with the evaluation test of the protection features.
EMC Pre-Compliance at a Glance
Every electronic 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
The PSU’s EMI emissions are in control.
