mhicks950
Member
- Location
- Stillwater, Oklahoma
- Occupation
- Chiller operator
Hello,
I work with industrial chillers and today had an odd experience with one of our pumps that I'd like to understand more about, so here goes.
I had started the chiller and got it put into auto after adjusting conditions to normal operation. My primary pump was on for about 10 minutes when I noticed that the monitoring system was reading 0% on the motor speed. I knew it was incorrect right away because my chiller would have tripped without any flow to the evaporator. I went down to the VFD and the hz reading was at 0.0hz, but the speed percent was 49.6%. After a few more minutes, I noticed the percentage on the monitor start coming up slowly, so I went back down to check the VFD. The monitor was communicating the hz reading rather than the speed percentage. After it slowly climbed up to 29.5 hz, the speed began increasing and the reading I got from the monitor was in sync with the motor speed rather than the frequency. I hope my explanation isn't too vague because I'd really like to get some answers as to why the monitor suddenly switched what reading it was communicating. The motor is a continuous inverter duty motor, in case that makes a difference. Thanks in advance for any insight. I've spent the last hour on the forum trying to piece together an answer with no luck.
I work with industrial chillers and today had an odd experience with one of our pumps that I'd like to understand more about, so here goes.
I had started the chiller and got it put into auto after adjusting conditions to normal operation. My primary pump was on for about 10 minutes when I noticed that the monitoring system was reading 0% on the motor speed. I knew it was incorrect right away because my chiller would have tripped without any flow to the evaporator. I went down to the VFD and the hz reading was at 0.0hz, but the speed percent was 49.6%. After a few more minutes, I noticed the percentage on the monitor start coming up slowly, so I went back down to check the VFD. The monitor was communicating the hz reading rather than the speed percentage. After it slowly climbed up to 29.5 hz, the speed began increasing and the reading I got from the monitor was in sync with the motor speed rather than the frequency. I hope my explanation isn't too vague because I'd really like to get some answers as to why the monitor suddenly switched what reading it was communicating. The motor is a continuous inverter duty motor, in case that makes a difference. Thanks in advance for any insight. I've spent the last hour on the forum trying to piece together an answer with no luck.
