Weird communication switch power failure

qlscool

Weird communication switch power failure [Copy link]

 

A set of Ningbo Longxing 600A communication 48V switching power supply, 3 50A rectifier modules, 20A load, two 500AH battery groups, AC voltage is confirmed to be normal, the three modules work for a period of time and then stop working at the same time, and then work again at the same time, the interval time is not fixed, it may be one or two minutes to twenty or thirty minutes, and it switches randomly between normal work and non-work all day long. The same is true when the monitoring module is unplugged, and the same is true when only one or two modules are connected. I racked my brains but still don't know how to explain it, so I would like to ask all the experts for help.

qwqwqw2088

Is there any load fluctuation or overload protection?
The load is displayed as 20A, which is far lower than the system supply design of 50A×3=150A carrying capacity, but it is necessary to confirm whether the load has a momentary overcurrent situation.

qwqwqw2088

Do you suspect poor heat dissipation?

There are also battery problems.
The battery status does not necessarily directly affect the operation of the rectifier module, but abnormal charging or discharging may affect the operation.

led2015

It may be a problem with the power input, rectifier module failure , control logic abnormality , battery pack impact, environmental factors, external interference , monitoring module and power system compatibility

qlscool

qwqwqw2088 posted on 2024-9-19 13:14 Is there any load fluctuation or overload protection? The load is displayed as 20A, which is far lower than the system supply design of 50A×3=150A carrying capacity, but it needs to be confirmed...

The load is constant, with very small fluctuations that can be ignored.

qlscool

led2015 Published on 2024-9-19 21:08 It may be a problem with the power input, rectifier module failure, control logic abnormality, battery pack influence, environmental factors, external interference, ...

The AC input has been confirmed to be fine, and the same is true after the monitoring module is unplugged. Environmental factors and external interference can be ruled out. The problem is in the power supply itself, but it is difficult to understand. Module failure is possible, but I don’t know how to explain that three modules stopped working at the same time.

qlscool

qwqwqw2088 posted on 2024-9-19 13:16 Do you suspect that the heat dissipation is poor? There is also a battery problem. The battery status does not necessarily directly affect the work of the rectifier module, but abnormal charging or discharging can...

When the rectifier module started working, the charging current was quite large, and then it slowly decreased. However, the module stopped working before the equalization charging was completed, and the battery discharge performance seemed normal. The ventilation and heat dissipation conditions were good, but because it was in the equalization charging state, the module fan sounded like it was running at full power, and the actual temperature felt on site was normal.

qlscool

I thought of a possibility. For some reason (factory quality problems, lightning strikes, etc.), the actual power supply capacity of the three modules cannot reach the nominal 50A. Therefore, even if the two sets of batteries are charged and the load is about 120 amperes, the three 50A modules still cannot run at full power. After a period of time, the high temperature or other protection will shut down. However, this explanation is a bit strange that the three modules work and shut down at the same time. It is too coincidental. In the case where the module cannot carry the load, it is common that the battery and the module are powered together, and the module will not shut down.

Originally, adding a few modules could verify whether this was the cause, but I don't have any spare modules, so I plan to unplug a set of batteries today and report back.

Gen_X

It seems that one of the battery groups has a single short circuit, so the DC cannot continue to work when the AC is disconnected. When the AC is present, in addition to the module, it also needs to continue to charge with a large current (the battery may be full, but the total voltage is not enough), so after a while, it will be overloaded (overheated) and protected, resulting in intermittent operation.

beyond_笑谈

Are there any photos of the complete system working? If the product is a communication power system (similar to a cabinet), and the power module is inserted into the power system, then it is necessary to check the feedback signal of the communication power system.

beyond_笑谈

According to Delta's design experience in communication power systems, the power module is a hot-swappable unit, and the system output is controlled by the control module of the communication power system.

beyond_笑谈

The three modules stop working at the same time after working for a period of time, and then work again at the same time after a while, with an irregular interval

//According to the description of the phenomenon, the power modules start/stop working at the same time. Basically, the power module problem can be ruled out first. Or you can unplug one/two of the three power modules and use the elimination method to verify