Page 329 - CITS - Electrician - Trade Practical

ELECTRICIAN - CITS

EXERCISE 112 : Visit HT/LT substation, identify various

parts of relay and ascertain the operation

Objectives

At the end of this exercise you shall be able to
• identify the external controls and parts of electromagnetic relay
• identify the internal parts of the single pole over current relay.
Requirements

Tools/Equipments/Instruments
• Trainees tool kit - 1 No.
• Single pole over current/earth fault relay
with instruction manual - 1 No.
Procedure

TASK 1 : Identify external controls and parts of a electromagnetic relay

1 Locate the relay parts provided in front of the relay (Fig 1) and identify the parts and fill in Table 1.
2 Note down the tap setting of current ranges at Table 2.
3 Note down in Table 2 the Indication displayed in the dial, multiplier along with percentage of fault current
tripping time.
4 Locate the tripping. Flag indicator resetting level provided in front panel.
Note: Once the relay tripped the flag will indicate a red line once it is tripped needs manual resetting
by operating the lever.

Table 1

Sl.No. Part No. Name of the external part Function

1 1 Tripping flag indicator Display tripping condition
2 2

3 3
4 4
5 5

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