Dear All, Is it mandatory to use VFD based controllers with Electric Motor driven Fire Pumps? Is NFPA-20 recommended the same or not? We proposed Wye-Delta type controllers for one of the project here in UAE but consultant asking for VFD based controllers type. Also, anyone could explain what are the Merits and Demerits of using the VFD based controllers?
Thanks in advance for your Advice & supports.

I sell both fire and municipal pumps and controls, including VFD's. Lots of consultants in municipal spec VFD's because they are relatively inexpensive and they can make up for a lot of sizing mistakes in HVAC/municipal applications. The run-cycle of fire pumps vs. these other pumps also makes the HVAC/muni VFD much more cost effective as it controls the energy consumption of pumps that run continuously. In fire VFD's are much more expensive, but are a good fit in the right application. As above, they help solve issues with excessive pressure. I have never had a project in which their use was mandatory, but a couple of projects where it was the best fit.

I agree with both comments but would not use unless I had a good reason from an eneering stand point.

Darrell

No it is Not mandatory, but good to use to adjust pressure in Piping.

Hi Eby,
I suppose that when you propose obsolete wye-delta type controller, the consultant proposes the VFD type controller.
Is wye-delta type required due to the potential of the motor???
Is VFD really required due to the variation of pressure???
Carvajal