HeaderedPumps:Variable Speed Operating at Constant Speed

I'm working on a model with variable speed headered condenser water pumps.

I've used the HeaderedPumps:VariableSpeed with 2 pumps per bank, and have input values for the total rated flow and Rated Pump Head.

After running the model I've had a look at the Pump Electric Power output which shows the pumps are operating at constant speed.

Has anyone experienced this issue before? I'm unsure as to why the pumps are not operating at variable speed.

JohnD's avatar
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JohnD
asked 2016-07-25 03:03:15 -0500
__AmirRoth__'s avatar
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__AmirRoth__
updated 2017-05-04 06:53:44 -0500
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What do you have on the demand side of your plant loop?

Julien Marrec's avatar Julien Marrec (2016-07-25 06:47:43 -0500) edit
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There are chillers, cooling towers, building load etc. (this is a model of a complete building.)

JohnD's avatar JohnD (2016-07-26 02:08:33 -0500) edit
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how are the chillers operated? They would need to be staged sequentially to see varying condenser flow.

Archmage's avatar Archmage (2016-07-26 07:43:33 -0500) edit
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There are 3 chillers each with its own variable speed pump - looking at the chiller flow and evaporator cooling rate profiles it seems they are staging as expected

JohnD's avatar JohnD (2016-07-26 18:19:27 -0500) edit
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Are your pumps in mode "Continuous"? Are they oversized? I'm thinking they could be running at the minimum speed all the time (shooting in the dark here)

Julien Marrec's avatar Julien Marrec (2016-07-27 02:44:20 -0500) edit
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