Answer / avd

Cold start : Starting the motor when it is cold. Means when
motor stoped and starts after long delay, considered as
cold start. Techanically if motor thermal containt is less
than 50%, it is considered cold.

Hot start : When motor is hot and you give start. Means
stoping the motor and immediately restarting is hot
start.Techanically if the motor thermal containt is more
than 50% and a start is given to motor, it is a hot start.

Effect : Any start of motor will result in increase of
thermal containt. If motor is hot (hot start given) than
motor thermal containt further increase hence there will be
detorioration in the insulation and thus life of motor.

Answer / sophia

Hot start and cold start refer to the temperature of the motor when starting. Hot start is usually a restart after coasting to a stop. Cold start is an initial start, after not having run for a relatively long period of time. This is important because there is usually a limit on the number of hot starts that are allowed in a certain period of time. This is due to the fact that these motors pull more current starting than when they run, and if you start them too often they can overheat.

Answer / mohamed

COLD : motor @ ambient temperature•
HOT : motor @ rated temperature for specific class and service factor.

Answer / mrudang

cold start its first start of motor
when the first time u start the motor

hot start of a motor means
second start of motor , after first start of motor u stop
the motor and again u start the motor then motor condition
is hot thats why it is known is hot start

prformance ???
when u start at cold condition , motor takes more starting
current for getting in synchronus condition

and in hot condition motor is already hot thats y it's
starting easy then cold

what are problems caused by the pdu in rack server

0 Answers  

---

what is open star connection or open delta.

1 Answers   ACC, Jindal,

---

Is phase preventer require when overload relay is there

1 Answers  

---

Why are calling leading power factor is a capacitive load?

1 Answers  

---

In 400KV Switchyard, we have used Circuit Breaker With PIR, what is the significance of PIR & why they'r used?

2 Answers  

---

I'm generating a pulse of 3V with frequency 80Hz (12.5ms time period) and pulse duration 0.125ms and feeding it to a transformer since i want the pulse to get amplified around 60V. At the output amplification s happening but the pulse is changed to a spike, can you tell me what could be the reason? (an ordinary transformer 220V-12V stepdown transformer is reverse connected ie. now it is 12V-220V stepup and voltage amplification happens)

0 Answers  

---

what is the setting of locked rotor in HT motor ? (answer expecting in percentage)

0 Answers  

---

what are the protection components on HT Side and LT side?

2 Answers  

---

What effect does a very low impedance have on the Voltage regulation? On the short-circuit current?

0 Answers  

---

suppose generator rating is 50 kw,load is 25 kw,hw much d generator ll generate?what about d remainin power?

2 Answers   NHPC,

---

Any link for Electrical objective type questions ?

0 Answers  

---

As we know induction squirrel cage motor torque Directly praprortinal to applied voltage in star connection & delta also. If I connect 55KW Motor to DOL starter in load condition does motor withstand the load & what will be the current withdrawn ? motor will not fail ?

0 Answers  

---