---
title: "220/2200 V transformer test parameters"
subject: "Electrical Machine"
chapter: 2
key: "semester_4/electrical_machine:transformer-220-2200-test-primary"
source: https://www.bctengineer.com/q/semester_4/electrical_machine/transformer-220-2200-test-primary
site: BCT Engineering
---

# 220/2200 V transformer test parameters

Electrical Machine · Chapter 2: Transformer

- Asked in: 2072 Magh
- Video: [(E)EM Ex 2.2 || Equivalent Circuit of a Transformer || Refer to Pri & Secy sides ||Open-Short Test](https://www.youtube.com/watch?v=uJP_rFndPtU) — Electrical Engineering Academy
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_4/electrical_machine/transformer-220-2200-test-primary
- Whole chapter: https://www.bctengineer.com/md/semester_4/electrical_machine/chapter-2

## Question

The no-load test and short circuit test on a 220 V/2200 volt single phase transformer gave following results.
No load test (on L.V side): 220 V, 1.2 Amp, 100 watts
Short circuit test (on HV side): 110 V, 8 Amp, 300 watts
Calculate equivalent circuit parameters refer to primary side and draw the equivalent circuit.

## Short answer

From no-load test: Ro=484 Ω, Xo=198.1 Ω. Short-circuit parameters referred to primary: R01=0.0469 Ω, X01=0.129 Ω.

## Answer

**Given:** 220/2200 V. No-load (LV side): 220 V, 1.2 A, 100 W. SC (HV side): 110 V, 8 A, 300 W. Primary = LV side (220 V); K = 2200/220 = 10.

#### Shunt branch (already on primary)
```text
cos φ0 = 100/(220 × 1.2) = 0.3788
Iw = 1.2 × 0.3788 = 0.4545 A
Iμ = √(1.2² − 0.4545²) = 1.1106 A
Ro = 220/0.4545 = 484 Ω
Xo = 220/1.1106 = 198.1 Ω
```

#### Series branch
On the HV side: Z02 = 110/8 = 13.75 Ω; R02 = 300/8² = 4.6875 Ω; X02 = √(13.75² − 4.6875²) = 12.93 Ω.

Referred to the primary (÷ 100):
```text
Z01 = 0.1375 Ω ;  R01 = 0.0469 Ω ;  X01 = 0.1293 Ω
```

#### Equivalent circuit (primary = 220 V side)
```text
        R01=0.0469Ω  X01=0.1293Ω
 o──┬────┬────/\/\/──────(((───────o
    │    │                          
  484Ω  198.1Ω                  load
    │    │                       V2'
 o──┴────┴───────────────────────────o
```
**Answer: Ro = 484 Ω, Xo = 198.1 Ω, R01 = 0.0469 Ω, X01 = 0.129 Ω.**

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Which side is the primary (reference) side in this problem?
   A. The 2200 V side
   B. The 220 V (LV) side
   C. Either; no difference
   D. Neither
   Answer: B. Primary is the 220 V side. (Key point: Primary side)

2. What is Iw from the no-load test?
   A. 0.4545 A
   B. 1.2 A
   C. 1.11 A
   D. 0.3788 A
   Answer: A. cos φ0 = 100/(220 × 1.2) = 0.3788; Iw = 1.2 × 0.3788 = 0.4545 A. (Key point: Iw)

3. R02 = 4.6875 Ω on the HV side. R01 on the primary is:
   A. 468.75 Ω
   B. 0.469 Ω
   C. 0.0469 Ω
   D. 4.6875 Ω
   Answer: C. Divide by K² = 100. (Key point: Series referral)

## Close variants set in other exams

- [20 kVA 250/2500 V test parameters](https://www.bctengineer.com/question.md?key=semester_4%2Felectrical_machine%3Atransformer-20kva-250-2500-primary) — Electrical Machine, chapter 2, asked 2×

## Related in Electrical Machine

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## Related in other subjects

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