I'm attending ETI right now and I was wondering if anyone could give me a crash course on relays and sequencers in an electric heat furnance or any other furnaces?
m1--------m2 Time delay
m1-to (1)side of breaker
m2-to (1)side of heat strips
m3-to (2)side if breaker
m4-to (2)side of heat strips
w-to white or w2 at thermostat
c-common side of transformer
'Life begins with the journey each day'
relays & starters & contactors & sequencers allow a small amount of current to switch on | off a larger amount of current. some have builtin time delay = time delay after circuit is shut off, or time delay before circuit is turned on -- control voltage may be anything from 2v to 440v, large current may be from 5 - 2000 amp. small current thru a coil activates plunger to close heavy duty contacts. Or, the whole thing may be solid state -- same principle --
TDO commonly used to hold down total current from supply side devices at one instant.
I was taught to think of a relay as a messenger it needs to relay a message ( elctricity ) to somewhere else when it is told to ( coil is energized ).
Get an old relay and take it apart.
do the same with sequencers,
It may help you to understand them
If you try to fail, and succeed.
Which have you done ?
I have a degree in commercial electricity and can follow this entire thread, but what I don't know is WTH is "ETI"?
Sory for using an analogy, there is a technical explanation for relays in any basic electricity book you can pick-up
I have found that using analogies helps people get started then there talent takes over once they have a general idea of what a components job is.