Special Control Cicuits

Question 1

3 basic types of timers?

Answer 1

Spring wound
Mechanical/electrical time switches
Timing relays

Question 2

Spring wound timers can be used for?

Answer 2

Lights
Bathtub spa motors sauna

Question 3

Mechanical timers
3 things about them

Answer 3

Electrically driven clockwork
Adjustable trip mechanism
Cams

Question 4

Timing relays

Answer 4

More acurate
Controlled by pneumaticslly air pressure
Or dashpots

Question 5

Dashpots?

Answer 5

Control the rate gas or liquid flows thru a home between chambers

Question 6

TDOE are good from ____ seconds to ____ hours

Answer 6

0.05 sec
300 hours

Question 7

TDOE other names?

Answer 7

On delay
Delay of realase

Question 8

TDOD other names?

Answer 8

Off Delay
Delay on release

Question 9

3 timing functions?

Answer 9

Interval
One shot
Repeat cycle

Question 10

Interval timing changes condition _____ but stay changed for a specified timing period

Answer 10

Immediately

Question 11

One shot requires

Answer 11

Power to be applied to the relay and to the start terminal of the relay

Question 12

One shot timing example

Answer 12

Auger to run a set time when a bin fills

Question 13

TDOE timing relay is first energized what are the conditions of?
NO
NC
NC IC

Answer 13

NO = OPEN
NC = closed
NC IC = open

Question 14

When TDOD is first energized what condition would be for
NO
NC
NC IC

Answer 14

Open.
Closed
Open

Question 15

TDOD has timed out what condition of
NO
NC
NO IC

Answer 15

Closed
Open
Closed

Question 16

TDOD has been deenergized
NO
NC
NO IC

Answer 16

Closed
Open
Open

Question 17

Why isna timing relay used in a wye Delta?

Answer 17

Slow stsrt up and come up before goes to delta

Question 18

Brake mechanism is held close or open by spring tension

Answer 18

Held close

Question 19

Dynamic braking/ magnectic braking

Answer 19

Motor stopped as if it was connected as a generator

Question 20

Ac braking is called?

Answer 20

Dc injection braking
Done in the stator

Question 21

Mechanical friction braking solenoid is connected in _____ with motor leads

Answer 21

Parallel

Question 22

Why are motor breaks used on large ventilation fans?

Answer 22

Prevent going backwards when de energized

Question 23

Braking that is used in induction motors?

Answer 23

Plugging

Question 24

Anti plugging used for?

Answer 24

Protect motor from being revered before motor has slowed to near zero

Question 25

Anti plugging switch NO or NC

Answer 25

NC SWITCH

Question 26

Control transformer used for 2 reasons?

Answer 26

Safer voltage
Isolate control cct from power cct

Question 27

What terminals for a electric brake in parallel with a 3 phase motor

Answer 27

T2 t3

Question 28

Whats required when using anti plugging on a 3phase motor

Answer 28

Anti plugging switch
Normal equip

Question 29

Anti plugging can be applied to?
3 ohase with anyload?
Single phase
Certain 3 phase motors

Answer 29

Any 3phase with a load

Question 30

Secondary is usually grounded on a single winding transformer to terminal

Answer 30

X2

Question 31

When anti plugging is applied to a motor it will ____ to a stop

Answer 31

Coast