Meggitt RPS6U power supply

Deployment and Maintenance of Meggitt RPS6U Power Supply in VM600Mk2/VM600 System

In the protection and status monitoring system of rotating machinery, the rack power supply is often not the most prominent component, but directly determines the availability of the entire monitoring chain. The VM600Mk2/VM600 series of Meggitt Vibro meter adopts the ABE04x standard 19 inch 6U system rack, and the RPS6U rack power supply is the core unit that provides+5 VDC,+12 VDC, and -12 VDC power to the rack and all module cards. For engineers who are working on system integration, spare parts replacement, or troubleshooting, understanding the power boundaries, redundancy logic, derating rules, and rear panel differences of RPS6U is more important than simply remembering the model.

The RPS6U adopts a front insertion structure and is installed at the front of the ABE04x rack. It is connected to the VME bus of the rack backplane through two high current DIN 41612 H15 connectors. The power output is not only used for a certain type of card, but is distributed to all installed modules in the rack through the backplane. Its rated weight is about 2.4 kg, with a working temperature range of 0-70 ° C, a storage temperature range of -40 ° C to 85 ° C, and a humidity of up to 90%. It is non condensing and suitable for indoor control cabinet environments. The internal of the power supply has been treated with a three proof coating for chemical, dust, moisture, and extreme temperature. The MTBF is greater than 40000 hours at 70 ° C, which determines its suitability for long-term online operation in mechanical monitoring scenarios.

Differences between electrical architecture and input versions

RPS6U is divided into three categories: AC input, 24 VDC input, and 110 VDC input. The AC version supports 115/230 VAC nominal input, with input ranges of 90-132 VAC and 180-264 VAC, and has automatic switching capability; It can also accept 178-264 VDC in conjunction with a specific rear panel with DC input. The 24 VDC version has an input range of 18-32 VDC, while the 110 VDC version has an input range of 80-145 VDC. The input frequency is only applicable to the AC version, ranging from 47 to 63 Hz. The AC version has a maximum input current of 6.4 A RMS at 115 VAC and 4 A RMS at 230 VAC; The maximum efficiency of the 24 VDC version is 30 A, and the maximum efficiency of the 110 VDC version is 6 A. The typical values of the three are 84%, 83%, and 85%, respectively, and the surge current is less than 10 times the nominal input current.

In terms of output, the current 330 W version offers a maximum of 50 A for+5 VDC, 8 A for+12 VDC, and 4 A for -12 VDC. Among them, the 24 VDC input version has a maximum of 6 A for+12 VDC. It should be emphasized that 330 W is the upper limit of the combined load, not a simple addition of three outputs loaded at the same time. For example, if+5 VDC reaches 5.35 V × 50 A ≈ 267.5 W, the total load of+12 VDC and -12 VDC should not exceed approximately 62.5 W. The factory adjustment point is approximately+5.41 VDC, ± 12.5 VDC, given at 60% maximum output power. The output ripple and noise are less than 50 mV peak to peak, the line adjustment rate is better than ± 1%, the load adjustment rate is better than ± 1% for+5 VDC, and better than ± 2% for ± 12 VDC. The power supply has output overvoltage protection and automatic locking, and short circuit and overload protection can be automatically restored. These protection logics are crucial for on-site diagnosis.

Single power supply and dual power supply: redundant and non redundant are not the same concept

The ABE04x rack can accommodate one or two RPS6Us. A single 330 W power supply can support non redundant operation of full rack module cards in an environment not exceeding 50 ° C. If two RPS6Us are installed, there are two completely different ways of use.

The first type is redundant configuration: two power supplies are online at the same time, and in the event of a fault in either one, the other can bear 100% of the power demand of the rack, while the rack continues to operate, thereby improving the availability of the monitoring system. This configuration is suitable for situations where monitoring capability cannot be lost due to a single power failure. However, it should be noted that the maximum current available under redundant configuration is still limited by the capability of a single RPS6U, and is not simply a combination of two power supplies.

The second type is non redundant configuration: two power supplies supply power simultaneously, but the purpose is not to backup for faults, but to support full shelf modules under high temperature or derating conditions. A typical scenario is when the ambient temperature is above 50 ° C and output power derating is required. At this time, the two power supplies share the load through the backplane, and the maximum available current is about 125% of that of a single power supply. The load distribution ratio is limited between 20% and 80%. Therefore, 'installing two power sources' should not be mistaken for' having redundancy '. Engineers must recalculate based on the number of rack modules, ambient temperature, and power supply version when expanding or replacing spare parts.