Internal Fault Error

[BillP]

Hi Guys,

I have several SMART-UPS 2000VA 120V which were returned back to us by our client for RMA. Majority of the UPSs are having "Internal Fault Error". Based on your experience guys, what are the possible causes of internal fault error in the UPS? Does frequency fluctuation affects the main UPS board?

As far as I am concerned, APC-UPS have a tolerance of ±3Hz, meaning it is capable to handle from 57-63Hz only. Unfortunately, once it exceeded its tolerance, it will give an alarm and will not charge the battery and will shutdown the whole system.

In this connection, I would like to know how can we rectify the problem of Internal Fault Error?

BR,

Arbie

[TheNotoriousKMP_apc]

The Control Board is not something that is to be worked on by an end-user. Therefore, the internal fault can only be determined by APC engineering.

[BillP]

Anyways, thanks for the advice. 🙂

[BillP]

Its quite complicated to narrow down what can cause an internal fault error in a UPS. Anything within the guts of the unit can have a malfunction, although I've seen that this error usually comes up after the UPS has been hit with a surge.

What type of environment are you keeping this units in? Input voltages, temperature, etc?
Are you monitoring these units via the Powerchute Software or Network Management Cards? The event logs might shed some light as to what is happening to these units.

[BillP]

I will give you an overview of the system. VSAT IDU equipments are connected to the UPS which input power (110VAC, 60Hz) mainly comes from generator. These VSAT IDUs are installed inside a cabin with airconditioning system. Some of the rigs, during drilling operations are having power frequency fluctuations ranging from 65Hz or even higher. When the UPS senses that its frequency is greater than or above the frequency threshold <58Hz or >63Hz, it will certainly bypass the main power input and will only work in battery mode. If it senses that the power frequency is again stable, it will go back to its normal operation. However, if it senses that the power is still not stable, eventually it will drain the batteries and will not be able to power on the UPS again and work in normal operation.

We do not monitor the UPS thru powerchute as we do not have the privilege to install application software to any business machines which are client caters and likewise there is no network management card installed in the UPS. We are sending our technician to investigate and troubleshoot the problem on site. So majority of the defective UPSs with Internal Fault Error might be related to power frequency variations.

Do you have any idea how we can rectify the problem of Internal Fault Error?

[TheNotoriousKMP_apc]

Based on the information you provided, it's very possible that due to the frequency drift on the input side of the UPS, the fault is caused by a failed inverter, battery charging circuit, or another Control Board component that works in conjunction with AVR or transferring to/from battery.

[BillP · Accepted solution]

So do you have any idea how to solve internal faults? Am sure it has an internal fault diagnostics and reporting. It's not even indicated in the manual or cd.