Customer: Minjingu Mines Fertilizers LTD
Location: Arusha, Tanzania
Equipment: DREAM DG-90G 90 kW Single-Stage Screw Air Compressor
A DREAM DG-90G 90 kW single-stage screw air compressor was delivered to a fertilizer mining operation in Arusha, Tanzania. The site is industrial, with other heavy equipment running alongside the new compressor. Power supply comes from a 1600 kVA transformer, with a 770 kVA diesel generator as backup.
The customer started the compressor and immediately ran into trouble. Voltage dropped sharply—from 420V down to 360V—every time the unit tried to start. When they connected a 50 kVAR capacitor to stabilize the supply, the system would run for a few seconds then shut down with a low voltage alarm.
They also had a separate issue: the compressor would start in star mode but never transition to delta, stopping after about 12 seconds.
They reached out to DREAM’s support team for help.
Our support engineer walked them through a step-by-step remote diagnosis.
First, we asked them to start the compressor with all other high-power equipment turned off. If the voltage still dropped significantly, the issue was likely on the supply side—either transformer capacity or cable impedance. If the voltage held steady, it meant other loads in the facility were consuming the transformer’s remaining capacity.
The customer reported that even with no load and the outlet closed, the voltage still dropped. They also tested with the 770 kVA generator and saw the same problem—voltage dropped from 400V to 360V.
We then asked them to measure voltage directly at the low-voltage side of the transformer, not just at the compressor’s control panel. If the transformer output was also dropping, the issue was upstream. If the transformer held steady but the compressor end still dropped, there was high resistance somewhere in the cables, switches, or terminals.
The customer checked and confirmed the drop was happening at the transformer itself.
They had already upgraded the incoming cable from 95 mm² aluminium to 95 mm² copper and confirmed the MCCB was rated at 650A—both adequate. The transformer was 1600 kVA, which should have been more than enough for a 90 kW compressor.
We concluded the issue was likely on the utility supply side—either the transformer was undersized for the combined load of the facility, or the high-voltage supply itself was weak.
The customer also reported that the compressor would start in star mode but never transition to delta, shutting down after 12 seconds. This is a classic symptom of either a control wiring issue or incorrect timer settings on the star-delta starter.
We provided remote guidance on checking the control circuit and confirmed the timer settings. After a few back-and-forth messages and some on-site checks, the customer resolved the issue.
The customer got the compressor running.
Here’s what they told us:
“Thank you, Dream Compressor Team! With your outstanding support and dedication, we successfully started our compressor today. We sincerely appreciate your valuable guidance and technical expertise throughout the process. Thank you for your excellent support!”
They also followed up with a request for the operation and maintenance manual and spare parts catalogue to plan for long-term reliable operation—a sign of trust and a long-term relationship taking shape.
This wasn’t a compressor failure. It was a site power supply issue—a 1600 kVA transformer that couldn’t handle the combined inrush current of the compressor along with other equipment on the same supply.
Our role was to help the customer diagnose the root cause remotely, rule out compressor-related faults, and get them operational. We didn’t sell them a new part. We helped them understand their own system.
That’s what good support looks like.
Not every startup issue is an equipment issue. Sometimes the problem is upstream—power supply, cabling, or site-wide load.
Remote troubleshooting works. With clear communication and step-by-step guidance, most issues can be diagnosed without sending a technician to site.
Good support builds trust. The customer didn’t just get their compressor running—they asked for manuals and spare parts lists to keep it running. That’s a customer who plans to stay.
Looking for Reliable Support with Your Compressor?
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