Wattman
Electrical
- May 2, 2001
- 24
An Application utilizes two pumps to fill a water tower. When the water level reaches the lower setpoint the first pump starts and runs until the high setpoint is reached at which the pump is stopped. (Just a typical pumping scenario.)
The cycle of the pumps appear to be a runtime of about 30 min then shut down for 20 min. But I'm sure this would vary somewhat over a 24/7 period. The water in the tower is used to supply water to a large industrial plant which operates 24/7, the demands of water usage depends on the number of boilers online and other process variables. The application probably does not have the demand changes that residential water customers would impose.
Question: The pumps use softstarts for starting and stopping, and I have learned that the power bill is approx. 2800 per month and feel that changing out the softstarts and installing A/C Drives would probably save power but I'm unsure of how to calculate the savings?
I would think allowing the pump to speed up/down to maintain a set level in the tower would be best. And I understand some of the complications involved with the pumps operating at a slower speed.
I plan to install a data logger to record the starting and stopping of the pumps with time and date stamps in order to evaluate the application, and I feel there would be more advantages than the power savings alone.
Is there a "Rule of thumb"????
Please Advise
The cycle of the pumps appear to be a runtime of about 30 min then shut down for 20 min. But I'm sure this would vary somewhat over a 24/7 period. The water in the tower is used to supply water to a large industrial plant which operates 24/7, the demands of water usage depends on the number of boilers online and other process variables. The application probably does not have the demand changes that residential water customers would impose.
Question: The pumps use softstarts for starting and stopping, and I have learned that the power bill is approx. 2800 per month and feel that changing out the softstarts and installing A/C Drives would probably save power but I'm unsure of how to calculate the savings?
I would think allowing the pump to speed up/down to maintain a set level in the tower would be best. And I understand some of the complications involved with the pumps operating at a slower speed.
I plan to install a data logger to record the starting and stopping of the pumps with time and date stamps in order to evaluate the application, and I feel there would be more advantages than the power savings alone.
Is there a "Rule of thumb"????
Please Advise