Substation - Substation 51, Kolnakos

 

On the 4th of June 2007 at 14:00 pm magnetic field measurements were performed for Substation 51 Kolnakos.

The substation is rated at a nominal power of 1000 KVA. At the time when the measurements were performed, the substation load power was recorded as:


Red Phase

Yellow Phase

Blue Phase

265A

245A

255A

Table 1: Measured load current

The resultant load of all three phases was 18% utilization of the nominal load current.

 

Limiting exposure values have been provided by the ICNIRP recommendations and are guidelines to many countries and organizations. The exposure limits at 50 Hz are tabulated in the following table according to the limits given by ICNIRP.

Reference levels for Occupational exposure ICNIRP

Frequency

Electric Field Strength, E (V/m)

Magnetic Field Strength, H (A/m)

Magnetic Flux Density, B (µT)

50 Hz

10000

400

500

Reference levels for General Public exposure ICNIRP

Frequency

Electric Field Strength, E (V/m)

Magnetic Field Strength, H (A/m)

Magnetic Flux Density, B (µT)

50 Hz

5000

80

100

Table 2: ICNIRP Exposure limits for Occupational and General Public exposure

The obtained results for the RMS fields inside and outside the substation are shown in tables 3 and 4 respectively. A comparison is also made with the ICNIRP recommendations.

 

Inside Field Measurements

Distance from Side /m

Maximum Magnetic Field at Z Height /m - Percentage of ICNIRP General Public Standard /%

0.3m

ICNIRP %

1m

ICNIRP %

1.75m

ICNIRP %

0.5m from right side 

48.87

9.77%

54.68 

10.94%

43.15 

8.63%

0.5m from right side

170.31

34.06% 

185.30

37.06% 

58.94 

11.79%

Table 3: Magnetic Field Measurements inside area

Outside Field Measurements

Distance from Side /m

Maximum Magnetic Field at Z Height /m - Percentage of ICNIRP General Public Standard /%

0.3m

ICNIRP %

1m

ICNIRP %

1.75m

ICNIRP %

0m from Front Side

8.17

8.17%

12.45 

12.45%

4,28 

4.28%

1m from Front Side

0.91 

0.91%

1.28 

1.28%

1.22

1.22%

2m from Front Side

0.39

0.38%

0.38

0.38%

0.36 

0.36%

Table 4: Magnetic Field Measurements in the outside area