Comments/Questions
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- The Cerus Industrial team
- The Cerus Industrial team
the P series drive we installed mid-summer for a deep well application has been working fine until today. the pressure builds so high it blows the relief valve at the pressure tank. pressure transducer right? anything special about this tranducer? what is the max pressure of the sensor? could it be something else?
Hi Steve,
You're right, usually in the situation you've described, the problem is that the pressure transducer has failed and is no longer sending a signal to the drive. The drive interprets a zero feedback signal as no pressure in the lines and ramps up to full speed trying to increase the pressure in the system. Do you have a part number for the transducer that is being used? There are multiple styles and ranges of transducers sold by Cerus alone and, in many applications, the customer opts to purchase the transducer separately as well so, without the part number, there is no way for us to provide detailed information on the transducer that is currently installed in your system.
There are other possible causes for this problem as well but a failed transducer is the most common cause in these situations. The simplest way to tell for sure is to look at the FBK value on parameter DRV-18 on the drive. This is a 0-60Hz display based directly on the feedback signal that the drive is seeing from your transducer. So, for example, if you’re using a 0-100psi 4-20mA transducer and your system pressure is currently at 40psi, you should see 24.00Hz as the FBK value on parameter DRV-18. The REF value on parameter DRV-18 is your desired pressure set point (entered on DRV-00) displayed in a 0-60Hz value as well so, put simply, the drive will be trying to adjust it’s output speed to make the FBK value match the REF value. If the FBK value is lower than the REF value, the drive increases it’s output in an attempt to bring the FBK value back up to the same level as the REF value and vice-versa.
If you continue to have difficulty troubleshooting the problem it can be very helpful for someone who is actually in front of the drive to call us up and we can help walk them through specific troubleshooting steps over the phone. If you have any questions or if there is anything else I can help you with please let me know. I am available Monday - Friday 7:30A.M. - 4:00P.M. Pacific Standard Time.
Sincerely,
Ethan N. Broten
Technical Support Representative
Direct: 503.906.1214
Toll Free: 1.800.962.3787 ext.214
Fax: 503.643.4925