two pumps in series with one vfd for one pump
two pumps in series with one vfd for one pump
(OP)
hi everybody,
can i use two pumps in series : one with constant speeed and the other with vfd?why?
can i use two pumps in series : one with constant speeed and the other with vfd?why?





RE: two pumps in series with one vfd for one pump
RE: two pumps in series with one vfd for one pump
RE: two pumps in series with one vfd for one pump
"Venditori de oleum-vipera non vigere excordis populi"
RE: two pumps in series with one vfd for one pump
yes this is done in certain circumstances, normally to avoid the cost of two VFDs but have some measure of flow control without throttling. It can make a lot of sense on a system where around 50% of the head is static lift and 50% is friction.
The normal area of debate is which pump should have the VFD. I tend to favour the first stage pump for ease of priming and less likelihood of accidentally producing a partial vacuum.
Cheers
Steve
RE: two pumps in series with one vfd for one pump
i have already replaced my old 1 from 2 cooling tower pumps with pump has 20% higher head,so i want to keep this pump without trimming and install another pump with the same data and fvd.
thanks.
RE: two pumps in series with one vfd for one pump
"Venditori de oleum-vipera non vigere excordis populi"
RE: two pumps in series with one vfd for one pump
Much cheaper options are,
1. Purchasing a new impeller
2. Controlling the discharge valve
Regards,