Laboratory work 2 automatic backup connection device

LABORATORY WORK 2
AUTOMATIC BACKUP CONNECTION DEVICE
Purpose of work - relay protection and automation construction and operation of used time, interval and indicator relays get acquainted with; to examine their main characteristics.
THEORETICAL CONCEPTS
Time relay protection or automatic executive body generate the delay time required for proper operation service to do.
Intermediate relays can perform the following tasks: To work controlled by a single contact of the pull-down relay increase the number of chains; separating different chains from each other or combine; connecting and disconnecting alternating or constant current chains;
Indicator relay relay protection or automatic operation return service is required. Voltage of time relays type EV-100. It is produced for 24, 48, 110 and 220V constant current. EV 200 type relays with voltage 100, 127, 220 and 380V released for use in alternating current circuits.
One of the main requirements for a time relay is its accuracy. The time error should not be greater than + 0.25 s. The time relay is reliable from 80% of the nominal voltage should work. Nowadays, even solid state time relays is being used. In them, the conduction time is through the resistor of the capacitor is generated based on the charging time to a certain voltage.
Semiconductor time relays VL-27, VL-37, RV - 01 and RV -03 type relays included.
TYPE OF WORK PERFORMANCE
1. With the structure of time relays intended for testing get acquainted and copy their passport data. Immutable EV-100 series and alternating current used in current circuits EV-200 series time relays used in circuits are different from each other see how they differ.
2. To test the timing relay, assemble the circuit shown in Figure I.
3. Find the starting voltage of the time relay (relaythe smallest voltage at which the armature is pulled).
4. To the coil of the time relay 10 times the rated voltage measures the operation time of the relay:
a) the largest on the relay scale for time;
b) the smallest on the relay scale for time;
c) given time setting for

Figure 1. Timing relay test circuit.

Write the obtained results in table 1:

Scale according to installation, etc

Ordinal numbers of the experiment

S

%

the biggest...s

the smallest.s

given..s

The biggest error of the relay ..... s.

5. The power consumed by the time relay at the nominal voltage determine, for this, a milliammeter in series with the coil of the relay must be connected.
6. Make a conclusion about the serviceability of the time relay.
7. With the structure of the intermediate relays intended for wiring get acquainted and copy their passport data.
8. Apply voltage to the coil of the intermediate relay and start it and determine the return voltages (or currents).
9. Use an electrostopwatch to measure the working time of the intermediate relay define. For this, the time relay from the circuit shown in Fig. I, instead, it can be used by connecting an intermediate relay. Intermediate relay
Find the running time from 10 times while running and restarting and give the results of the experiment in Table 2.

Type of relay	Relay operation and return time, s
	When the relay is operating		When the relay returns
	Most of the 10 experiences		Most of the 10 experiences
	The biggest	The little	The biggest	The little

10 Get acquainted with the structure of the indicator relay and its check that it works by applying voltage to the coils.

WORK REPORT
The report states:
1) the purpose of performing the work;
2) passport data of used relays;
3) tables with experimental schemes and experimental results;
4) conclusion.
REVIEW QUESTIONS
1. What relays are included in auxiliary relays?
2. Functions of auxiliary relays.
3. Range designed for 110 V constant current
electromagnetic relay to the 110 V alternating current circuit
how does it work when connected?
4. There is an intermediate relay designed for 110 V constant current.
It should be used in a 220 V DC circuit. This how to do it?