SCR Heating Control
SCR Heating Control
(OP)
What would be the potential negative impact of imbalanced load on a 3 ph. 480 VAC SCR heating controller.
Heating load consists of multiple elements connected as 3 wire, wye connected - there is no neutral conductor run to the load so that the 'wye' point at the load end is floating.
Assuming the phase currents are not balanced due to design and/or heater element failure - are there any negative consequences to the SCR controller, assuming phase currents are maintained within the overall current rating? Is there a imbalance threshold where the SCR controller would malfunction and/or be damaged? (an open circuit on one phase?)
Heating load consists of multiple elements connected as 3 wire, wye connected - there is no neutral conductor run to the load so that the 'wye' point at the load end is floating.
Assuming the phase currents are not balanced due to design and/or heater element failure - are there any negative consequences to the SCR controller, assuming phase currents are maintained within the overall current rating? Is there a imbalance threshold where the SCR controller would malfunction and/or be damaged? (an open circuit on one phase?)





RE: SCR Heating Control
RE: SCR Heating Control
RE: SCR Heating Control
The one that gave me problems did not have any "slave" gating pulses to keep the return path open and could not work with wye connected loads without Neutral connected to star point.
But if the unit says that it can work with floating wye - no probs.
Gunnar Englund
www.gke.org
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Half full - Half empty? I don't mind. It's what in it that counts.
RE: SCR Heating Control
Was not sure if there was a potential negative impact on the SCR. The SCR has been working with the floating wye configuration for many many years. Issues on the load side are now causing the unbalanced load, and there were questions related to any potential for SCR damage. The responses so far are consistent with what I was thinking.