Circuit Wiring help.

[IrishSparks]

Hi.
I’m wiring a system whereby a limit switch sets off a flashing beacon to warn employees that a tank of bitumen is full. I have 6 tanks in total. I have it working no issues. The tank fills up and activates a limit switch which turns on a relay and the flashing beacon will come on. I’ve been asked now though to put a sounder on the circuit that will come in when any of the tanks relays are activated. They also want it wired that then can silence the sounder but leave the beacon flashing. I’m struggling to come up with a way to incorporate this into the circuit. Has anyone any ideas?
Thanks

 

[telectrix]

what voltage are the flashing beacons?

 

[IrishSparks]

what voltage are the flashing beacons?

Everything is 220v as in the power to limit switches and relays and power out to the beacons from the relays but the beacons have a mains module in the base which converts it to 24v DC

 

[IrishSparks]

I was thinking I could change the beacons to a combined sounder/beacon but I’d still need to be able silence the sounder and have the beacon stay flashing

 

[David Prosser]

Push button timer or key switch for sounder of the relay that activates the beacon.

 

[telectrix]

with D.C. you could have any 1 relay energising a new relay using diodes to block feedback. won't work with A.C. though.

members Lucien or Marconi might be your best bet.

 

[timbobelfast]

Hi.
I’m wiring a system whereby a limit switch sets off a flashing beacon to warn employees that a tank of bitumen is full. I have 6 tanks in total. I have it working no issues. The tank fills up and activates a limit switch which turns on a relay and the flashing beacon will come on. I’ve been asked now though to put a sounder on the circuit that will come in when any of the tanks relays are activated. They also want it wired that then can silence the sounder but leave the beacon flashing. I’m struggling to come up with a way to incorporate this into the circuit. Has anyone any ideas?
Thanks

Is this not a SIL requirement ? Upon Alarm activation are valves to close or pumps to cut out?

Be careful with this one........ A tank overfill will be classed as a major incident and if appropriate designs have not been risk assessed then it can come back to bite.
A PLC or PILZ PLC would be the way I would design this. Are the limit switches in the form of probes ontop of the tanks or what?

 

[Rockingit]

from a wiring persepctive only, if you put the sounder on a separate NO relay and do the usual loop of the supply L to latch it on, a momentary OFF in that loop will reset it until the next activation

 

[Darkwood]

Taking note of the last post by @timbobelfast as this could fall into a full risk assessment territory and safety category level in design, that aside if it falls below that then you can simply have each limit trigger an individual relay, run a common feed through the relays and have any output energise the sounder, a silence option would be a switch in the common supply to the relays.

 

[pc1966]

As @Darkwood says, a relay per beacon operated by the beacon power, and all the N/O contacts in parallel so any one acting closes that circuit, then through a muting switch to the sounder.

But I would have the mute switch as a push button and another relay (rather like a motor contactor no-volt release, but the other way), so once the original limit is released the sounder is automatically re-engaged until the next time.

Also as above, you need to have a clear assessment of the risk(s) and implications of a sensor failing, and hence if you need to have redundancy / fail-safe, etc.

 

[pc1966]

Here is one idea, but the usual disclaimers about verifying it meets requirements, actually having said requirements in writing from the customer, etc, etc, all apply:

Others might have better ideas, but this is fairly cheap and simple if existing stuff is all AC mains, and you can have the sounder isolated from the supply(s) to the limits switches (even though I have shown them all of the common L & N to the left, they could be different phases or fuse/MCB protection).

 

[timbobelfast]

Here is one idea, but the usual disclaimers about verifying it meets requirements, actually having said requirements in writing from the customer, etc, etc, all apply:
View attachment 85071
Others might have better ideas, but this is fairly cheap and simple if existing stuff is all AC mains, and you can have the sounder isolated from the supply(s) to the limits switches (even though I have shown them all of the common L & N to the left, they could be different phases or fuse/MCB protection).

Very unlikely that the tank high levels will be 230v, more likely 24 v and through an Is barrier.
. This setup would be easier managed through a Pilz or plc. Has the op came back with any further info?

I would have thought there would be pump cut outs or valve control aswell with a high level alarm.

 

[timbobelfast]

Something like this, with a N/O twist lock alarm silence button.......

 

[marconi]

I come from an industrial background and rarely did we design stuff we could buy off the shelf which had the valuable operational and legal benefits of being thoroughly trialled and tested, be certified by an appropriate authority, have specified functionality and performance, calibrated, an assessment of or demonstrated reliability, be fail safe and of course approved for a particular application. Why re-invent the wheel? There are many things which 'simple solutions' will fail to prevent happening and when they do.....

I advise you research and buy a suitable system off the shelf. For starters have a dekko at:

https://www.eurobitume.eu/public_do...auges_and_High_Level_Alarms_-_August_2019.pdf

 

[alexanderzingman]

Really a great thread thank you your suggestion and help on this.