Easy way to calculate transformer and motor details
Transformer details:
- Transformer size
- Transformer secondary voltage (v2)
- % Impedance (z)
- Allowable voltage drop in system
Motor details for one and more motors:
- Motor full load current (ILM)
- Locked rotor current multiplier (Min)
- Locked rotor current multiplier (Max)
- Locked rotor current (L1) (Min)
- Locked rotor current (L2) (Max)
- Motor inrush KVA at starting (IrsM)
- How many times motor starts per hour
and Calculations:
- Full load current of transformer (ILX)
- Short circuit current at transformer secondary (Isc)
- Maximum KVA of transformer at Isc (Q1)
- Motor inrush KVA At starting (IrsM)
- Voltage drop at transformer secondary due to motor inrush (Vd)
- Transformer secondary voltage
Results you get:
- Motor Full Load Current
- Voltage Drop at Transformer Secondary Due to Motor inRush
- Transformer Size:(20% Added due to motor starts more than once/Hour)
Calculation formulas used:
- ILX = KVA / (1.732 x v2)
- ILM = (Kw x 1000) / (1.732 x Vm x P.F)
- Isc = ILx / z
- Q1 = (v2 x ISC x ILM x 1.732) / 1000
- IrsM = (Vm x L2 x 1.732) / 1000
- Vd = IrsM / Q1
| Software: | Calculate size of transformer and voltage due to starting of large size motor |
| Version: | 10.6.13 |
| Developer: | Jignesh Parmar |
| Size: | 40 KB |
| Price: | Free |
| Download: | Right here | Video Courses | Membership | Download Updates |
how to size proper transformer for pump motor
Whether this calculation holds good for heavy starts as for ballmills.
Rule of thumb large motors should be ___ of the KVA of XFMR?