Answer Posted / daniel tan

The nuisance tripping either for 30mA or 100mA is not so
crucial when Hot water system is concern. With reference to
IEC60479, the RCD/ELCB 30mA or 100mA is not safe to be used
for the Hot water system where it could result to a shock
hazard. As declared by this Standard, a normal human body
can only withstand to a maximum of <7mA. The Residual
Current Device (RCD) leakage protection ranges between
2.5mA~5mA/<50mS should be the correct level of protection
for any Hot water system or Instant water heater appliances
at Home. To prevent any shock hazard, look for RCD can
perform 2.5mA~5mA/<50mS. Let me know if you need help.

How can we calculate the transformer rating if the load calculated is 1000KW (11Kv Supply)?

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why the neutral line is not giving shock to us if we touch it ?

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Dear all, I just want to ask an expert on this forum for some insights. For the magnetic balance test, when applied voltage on a Delta-Star transformer e.g. Dyn11, the following relationships apply for HV side: 1.  H1-H2 = H2-H3 H3-H1 2.  H2-H3 = H3-H1 H1-H2 3.  H3-H1 = H1-H2 H2-H3 For the LV side also: 4.  X1-X0 = X2-X0 X3-X0 5.  X2-X0 = X3-X0 X1-X0 6.  X3-X0 = X1-X0 X2-X0 Is there a similar pattern for Y-d, Y-Y, D-d? And how about Y-z, D-z, Z-y transformers? I've tested a YNzn5 transformer and for LV side I don't see the pattern. In this particular case I got for LV side the following (see values below): H1-H0  H2-H0  H3-H0    X0-X1  X0-X2  X0-X3 128.0  119.9  7.2      29.2   13.3   15.8 70.7   128.4  59.2     23.4   22.0   3.6 7.2    120.1  128.1    13.4   29.3   15.8 What is the relationship here for LV? For row 1 I see the relationship, for row 3 I also see but it's shifted, but for row 2 I don't see such relationship. Any suggestions, answers, someone?

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2220

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What technology is used in latest generators?

2077

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please send privious years question papers of jindal steel and power ltd.My e mail id is rajanikant.sngh@gmail.com

2084

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why incomer bay is required before transformer bay if there are more than 1 nos. of transformer bay.

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FOR 16/20 MVA 132/33 KV ONAN/ONAF TYPE TRANSFORMER IT IS DESIGNED FOR 16 MVA WITH ONAN CONDITION.IT BECOMES 20 MVA UNDER ONAF CONDITION.LOAD LOSS IS GUARANTEED FOR 65KW AT 20 MVA AND % IMPEDANCE 13.75. PLEASE TELL US AT WHAT LOAD LOSS AND % IMPEDANCE IT SHOULD BE DESIGNED FOR 16 MVA AND WHAT WILL BE ITS EFFICIENCY AT 20 MVA?

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1928

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2182

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1190

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1246

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1675

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