WebSize the wire for the main 480 VAC circuit based on the chosen main circuit breaker (60A) using the “Wire Size and Selection Criteria” blog post – 4 AWG wire Select colors using selection criteria: 480VAC Phase 1,2,3 – Brown + Orange + Yellow 480VAC Neutral – Grey 480 VAC Ground – Green WebJan 19, 2024 · According to the code 28.204 I don't exceed this for protection, I would use a 40A breaker and a 6AWG cable Analysis 2: I(total) = (VFD1+VFD2)x1.25 + HEATER = (14.9+14.9)x1.25+9 = 46.25 According to the code 28.204 I don't exceed this for protection, I would use a 45A breaker and a 6AWG cable I am thinking analysis 1 is correct.
How do you provide overload protection for variable-frequency drives …
WebMar 16, 2015 · The VFD mfrs are not concerned with what the protection for the VFD or the motor is when you are in Bypass. So your Bypass circuit is on its own so to speak. Many small VFDs are listed in series with the little self-protected starters because of cost and size, and because regular CBs will not come smaller than 15A anyway, which may be too large ... WebIn VFD Sizing, the main considerations are: 1. The VFD continuous current shall be higher than the motors’ current at maximum load. It is not necessary to size the VFD to the motor FLA rating if the motor application is oversized. eastgate mall shops list
Electrical design for HVAC systems - Specifying Engineer
WebOct 24, 2024 · Multi-motor applications may need to bump up one VFD size to accommodate the amps— To drive two 5hp/460v motors needs 7.6a + 7.6a = 15.2amps max. If you look at the 10hp/460v value in the table it is only 14amps max. In this example we may need a 15hp VFD to run those two 5hp motors. WebSep 12, 2011 · The engineer would then take the next smaller standard breaker size, below the derived OPD ampacity. In our case, the next smaller breaker, below 18 Amps, is a 15 Amp breaker. It is important to note that any OPD ampacity that is smaller than19.9 Amps will always use a 15 Amp breaker. WebApr 16, 2013 · To size conductors and OCPDs for branch circuits, follow the steps shown in Fig. 1. The steps for feeders modify the steps for branch circuits, as shown in Fig. 2. But if you have motor circuits, remember that the inrush current of motors changes things: The normal functions of the OCPD are split. culligan st joseph mo