Fuses, Breakers, Amps, Max Load... Crossy!

[Forkinhades]

^ indeed please

and please anser my previous questions, then we can possibly come up with a solution.

Thank you

[Naam]

^ that cannot be right?

surely the supply to the 'control' fuses is coming from the live side of the contactors?

picture not very clear, and think that goes against post 45?

so can we have confimation please what side of the contactor the control fuses are fed from.

please read what i wrote before. nothing, zilch, nada, rien, niente, nichts, muffat, mafeesh is coming from the contactors except uninterrupted power to the distibution panels if the solenoids close the contacts.

So can you advise where the supply is coming from that feed the 'control' fuses

Sorry but I have jumped in on this thread, and not read all the posts thoroughly, I am trying help. Will reread all the posts

here we go again:

incoming supply from top going into a channel on the right side

of the panel and from there up to MCB fuses (40A) and to (mistake deleted)

porcelain fuses (32A) (left). there's also one thick wire from down

going to the arrestors. all three gadgets are connected to the three

"timers/sensors" which show "on" as well as to three small relays

located below.

[Naam]

If I read Naam's earlier post correctly, power enters the board via the right hand contacts of the terminal strip, proceeds down the trunking on the right to the MCBs, from where it goes to the T1 terminal of the contactor, the load is fed via the L1 contactor terminal and exits via the left hand end of the terminal strip..

I think the fuses are fed from the T3 terminals and it still looks like T1 and T3 are linked on each contactor.

Please can Naam confirm these assertions?

i am not sure what to confirm because power to the contactors seems to be routed parallel via MCBs and porcelain fuses.

[Crossy]

The fuse 'feed' is the fat wire at the top, do you know where the other end of that wire goes? It looks like it goes to a contactor T terminal (T1 or T3?).

OR it could go to the surge arrestor, and then to the T terminal (it looks like the surge arrestor has two wires in each L terminal).

It would also be useful to know if the T1 and T3 terminals are linked like the L1 and L3 terminals.

[Naam]

i forgot to type the "h". the output capacity of each inverter is 2,000W, input is 24V supplied by 2 batteries each 160Ah (amphours) = 320Ah.

actually i installed the protection devices only to save on burned aircon and pump relays which i had to replace frequently in olden times due to brown-outs.

all our electronics are additionally protected by 3 inverters (not UPS toys but 320A each) which kick in when voltage deviates too much.

even though i am a "sparkie apprentice" i have a hard time not taking your advice of upgrading the cables to the outlets as a terrible insult. this time i will overlook the remark. next time expect my seconds to knock at your door and challenge you for a duel, "heavy sabres sine sine" on sunday morning at dawn in my front garden

2 x 12V 160Ah batteries in series to feed a 24V inverter deliver 24V 160 Ah.

advice from experts is always highly appreciated even if totally irrelevant to the thread

by the way, these are the new inverters to be delivered end of this month. have problems with the built-in chargers of the old ones. the new ones have an input of 12V.

[Crossy]

Without a diagram we are really going to struggle here trying to work out what's popping the fuses.

Knowing what we now know I would NOT replace with bigger fuses, but 30A MCBs would be OK and easier to reset should they open.

[Forkinhades]

^ ok do you any 3 phase equipment connected in the house?

[Naam]

The fuse 'feed' is the fat wire at the top, do you know where the other end of that wire goes? It looks like it goes to a contactor T terminal (T1 or T3?).

OR it could go to the surge arrestor, and then to the T terminal (it looks like the surge arrestor has two wires in each L terminal).

It would also be useful to know if the T1 and T3 terminals are linked like the L1 and L3 terminals.

sorry Crossy i am lost

[jbrain]

i forgot to type the "h". the output capacity of each inverter is 2,000W, input is 24V supplied by 2 batteries each 160Ah (amphours) = 320Ah.

actually i installed the protection devices only to save on burned aircon and pump relays which i had to replace frequently in olden times due to brown-outs.

all our electronics are additionally protected by 3 inverters (not UPS toys but 320A each) which kick in when voltage deviates too much.

even though i am a "sparkie apprentice" i have a hard time not taking your advice of upgrading the cables to the outlets as a terrible insult. this time i will overlook the remark. next time expect my seconds to knock at your door and challenge you for a duel, "heavy sabres sine sine" on sunday morning at dawn in my front garden

2 x 12V 160Ah batteries in series to feed a 24V inverter deliver 24V 160 Ah.

advice from experts is always highly appreciated even if totally irrelevant to the thread

by the way, these are the new inverters to be delivered end of this month. have problems with the built-in chargers of the old ones. the new ones have an input of 12V.

Just my 2 satang, but I wouldn't advise to use a 12V inverter to provide 3000W.

I also think that inverter picrured in your post doesn't have internal charger. Do you intend to use external chargers?

[Forkinhades]

The fuse 'feed' is the fat wire at the top, do you know where the other end of that wire goes? It looks like it goes to a contactor T terminal (T1 or T3?).

OR it could go to the surge arrestor, and then to the T terminal (it looks like the surge arrestor has two wires in each L terminal).

It would also be useful to know if the T1 and T3 terminals are linked like the L1 and L3 terminals.

Yes this is the confirmation I am after!

[Naam]

^ ok do you any 3 phase equipment connected in the house?

unfortunately yes because some àsshole of builder procured the roof exhaust fan and the whole-house fan with 3-phase motors although both are only ½HP

but in what way is your question related to the topic?

[Forkinhades]

Naam the 3 fuses on the left hand, each have a fat black cable going into them, with a colour band 'blue' 'red' and 'yellow' we need to know where it goes, to the top of contactor, bottom of contactor, or to the main strip at the top

[Naam]

The fuse 'feed' is the fat wire at the top, do you know where the other end of that wire goes? It looks like it goes to a contactor T terminal (T1 or T3?).

OR it could go to the surge arrestor, and then to the T terminal (it looks like the surge arrestor has two wires in each L terminal).

It would also be useful to know if the T1 and T3 terminals are linked like the L1 and L3 terminals.

Yes this is the confirmation I am after!

i can't answer because i don't understand your British syntax!

"fat wire" on top of "what"?

[Forkinhades]

^ ok do you any 3 phase equipment connected in the house?

unfortunately yes because some àsshole of builder procured the roof exhaust fan and the whole-house fan with 3-phase motors although both are only ½HP

but in what way is your question related to the topic?

trust me it is very related, as to getting a sloution, we can change phases on the load side, and see what fuse blows next time the fault occurs, if it is still the same fuse then it is a control issue ie either sensor or relay, if its a different fuse, then that would suggest a load issue.

[Crossy]

sorry Crossy i am lost

OK,

1. Left hand fuse, blue sleeved black wire at the top of the fuse, can you see where the other end of the wire goes?

2. Any contactor, is there a wire between the T1 and T3 terminals?

EDIT I see Forky is on the same tack

[Forkinhades]

The cable(s) entering the fuse carrier at the top of the 32amp HRC fuse, where does it go? top of contactor or botttom or strip at top of panel

[Naam]

Naam the 3 fuses on the left hand, each have a fat black cable going into them, with a colour band 'blue' 'red' and 'yellow' we need to know where it goes, to the top of contactor, bottom of contactor, or to the main strip at the top

from the fuses left and right colour marked cables enter the bottom of the contactors. the same applies to the cables from the surge arrestors. i can't make a better picture which would show that these cables are connected "piggy back" to the contactors.

[Naam]

The cable(s) entering the fuse carrier at the top of the 32amp HRC fuse, where does it go? top of contactor or botttom or strip at top of panel

everything from down (left fuses, right MCBs, surge arrestors) goes to the bottoms of the contactors. from the top of the contactors cables go to the distribution panels.

[Forkinhades]

sorry Crossy i am lost

OK,

1. Left hand fuse, blue sleeved black wire at the top of the fuse, can you see where the other end of the wire goes?

2. Any contactor, is there a wire between the T1 and T3 terminals?

EDIT I see Forky is on the same tack

[Forkinhades]

Naam the 3 fuses on the left hand, each have a fat black cable going into them, with a colour band 'blue' 'red' and 'yellow' we need to know where it goes, to the top of contactor, bottom of contactor, or to the main strip at the top

from the fuses left and right colour marked cables enter the bottom of the contactors. the same applies to the cables from the surge arrestors. i can't make a better picture which would show that these cables are connected "piggy back" to the contactors.

OK that is good that it is wired like, as I was struggling to see how it would work otherwise.

edit inserted work

[Crossy]

Naam the 3 fuses on the left hand, each have a fat black cable going into them, with a colour band 'blue' 'red' and 'yellow' we need to know where it goes, to the top of contactor, bottom of contactor, or to the main strip at the top

from the fuses left and right colour marked cables enter the bottom of the contactors. the same applies to the cables from the surge arrestors. i can't make a better picture which would show that these cables are connected "piggy back" to the contactors.

OK that is good that it is wired like, as I was struggling to see how it would otherwise.

Yup, so no load current should be going through those fuses, just the supply to the sensors, relays and contactor coils.

Now we are in trouble, because the yellow wires are not numbered

[Forkinhades]

So it is really pointing towards either sensor or relay problem. Dont think it would be the coil on the contactor.

[Crossy]

So it is really pointing towards either sensor or relay problem. Dont think it would be the coil on the contactor.

Agreed.

I'm not sure we can get much further here to be honest. It can't be a hard fault as the fuse stays intact for long periods. A Thai sparks would put in a bigger fuse and see what blows up

@Naam, you are getting your full 45A supply.

Do those sensors really need slave relays to drive the contactor coils, or is there another function being performed by the relays?

[Forkinhades]

Suggestions:

check wiring is the same on the sensor/relay (faulty) circuit as the other two

If same tighten all connections.

If still fails, change the sensor/relay on that circuit

[Naam]

sorry Crossy i am lost

OK,

1. Left hand fuse, blue sleeved black wire at the top of the fuse, can you see where the other end of the wire goes?

2. Any contactor, is there a wire between the T1 and T3 terminals?

EDIT I see Forky is on the same tack

Crossy have mercy! each time i walk 62m one way on top of my daily morning exercise.

left hand fuse "blue sleeved black wire" goes to left contactor. that applies accordingly to the yellow and red sleeved wired accordingly. one can't see it on the pictures and difficult to see it in

natura because the wires are connected under the wires going from the MCBs to the contactors.

the outside "contacts" of the contactors are "bridged" on top and bottom. the middle contact is "empty".

[Forkinhades]

It sounds like the fault happens when indeed the voltage drop by 10% and the control circuit kicks in, could be a lose wire, wrong connection, or faulty device sensor or relay.

You have 3 control circuits, 1 is bad for whatever reason. Look at the 2 good ones!! The items positions should be relative, but you will need to check that.

[Naam]

So it is really pointing towards either sensor or relay problem. Dont think it would be the coil on the contactor.

Agreed.

I'm not sure we can get much further here to be honest. It can't be a hard fault as the fuse stays intact for long periods. A Thai sparks would put in a bigger fuse and see what blows up

@Naam, you are getting your full 45A supply.

Do those sensors really need slave relays to drive the contactor coils, or is there another function being performed by the relays?

with the present setup? you mean i don't have to change to MSBs???

[Forkinhades]

sorry Crossy i am lost

OK,

1. Left hand fuse, blue sleeved black wire at the top of the fuse, can you see where the other end of the wire goes?

2. Any contactor, is there a wire between the T1 and T3 terminals?

EDIT I see Forky is on the same tack

Crossy have mercy! each time i walk 62m one way on top of my daily morning exercise.

left hand fuse "blue sleeved black wire" goes to left contactor. that applies accordingly to the yellow and red sleeved wired accordingly. one can't see it on the pictures and difficult to see it in

natura because the wires are connected under the wires going from the MCBs to the contactors.

the outside "contacts" of the contactors are "bridged" on top and bottom. the middle contact is "empty".

Naam think we can ignore that now. I am sure we have pinned it down

[Forkinhades]

So it is really pointing towards either sensor or relay problem. Dont think it would be the coil on the contactor.

Agreed.

I'm not sure we can get much further here to be honest. It can't be a hard fault as the fuse stays intact for long periods. A Thai sparks would put in a bigger fuse and see what blows up

@Naam, you are getting your full 45A supply.

Do those sensors really need slave relays to drive the contactor coils, or is there another function being performed by the relays?

with the present setup? you mean i don't have to change to MSBs???

Correct. I think the fault happens when the sensor kicks in, thus taking out the control fuse. Everthing will work fine untill the 'sensor' has been switched

[Naam]

It sounds like the fault happens when indeed the voltage drop by 10% and the control circuit kicks in, could be a lose wire, wrong connection, or faulty device sensor or relay.

You have 3 control circuits, 1 is bad for whatever reason. Look at the 2 good ones!! The items positions should be relative, but you will need to check that.

for one incident in five years i don't do anything because i'm not qualified to do the check and i don't know where to find a qualified electrician.

replacing the fuse and the melted holder takes 3 minutes. i have spare fuses as well as spare holders.

but the question is still whether i can replace these fuses with MCBs because i would save 2 minutes 59 seconds of work by flipping the tripped MCB if it happens again.

now tell me something interesting how my two 3-phase gadgets come into the picture although i have plans to replace the motors with single phase units.