Heaters for fishtanks

[Brando]

Hi, I've being asked to provide pwer for multiple fish tank heaters about 20 of them just thinking of running 3 or 4 radials on rcbos
Any ideas

 

[telectrix]

can't be much over 1kW for the lot. why separate circuits?

 

[pc1966]

Unless this is for Dr Evil's shark tank I guess each heater is going to be only tens of watts so total load is unlikely to be an issue.

Reliability might be if they are rare/expensive fish that can't stand a heating outage though. Having dual heaters for each tank that are fed from separate RCBO radials might be an option there, but you would also need some warning that one half has gone down otherwise its only a matter of time before the other side trips and nobody was aware the redundancy had been lost. A pair of prominent power indicators might be OK for that.

 

[Moley]

Depending on the size of the tank the heater could be anywhere between 50W and 300W. Once the tank is up to temperature and assuming the tank is in a reasonably warm room the heater spends more time off than on (or at least ours do). Now the one in the Koi pond does spend most of it's life on at the moment.

 

[Brando]

Unless this is for Dr Evil's shark tank I guess each heater is going to be only tens of watts so total load is unlikely to be an issue.

Reliability might be if they are rare/expensive fish that can't stand a heating outage though. Having dual heaters for each tank that are fed from separate RCBO radials might be an option there, but you would also need some warning that one half has gone down otherwise its only a matter of time before the other side trips and nobody was aware the redundancy had been lost. A pair of prominent power indicators might be OK for that.

Hi was looking to put a link also to the alarm system so I maybe it can activate a remote alarm to tell someone there may b an issue

 

[pc1966]

Hi was looking to put a link also to the alarm system so I maybe it can activate a remote alarm to tell someone there may b an issue

Most alarms have the option for normally-closed contacts so a door opening (or cable cut) shows up. You could use some normally open contacts on a 230V relay so on power fail it opens the alarm circuit, ideally with enough contacs in the alram so it is clearly identified as to which RCBO has tripped, etc.

 

[Brando]

Most alarms have the option for normally-closed contacts so a door opening (or cable cut) shows up. You could use some normally open contacts on a 230V relay so on power fail it opens the alarm circuit, ideally with enough contacs in the alram so it is clearly identified as to which RCBO has tripped, etc.

Just need to figure out how to wire through rcbos as there's no auxiliary contacts open or closed

 

[pc1966]

Just need to figure out how to wire through rcbos as there's no auxiliary contacts open or closed

Just put the 230V relay coil(s) on the RCBO output(s) then on power fail the relay opens and you can use the contacts to tell the alarm in a suitably isolated manner. I have used the following in a Hager TPN board and it fitted (just) height-wise:

90.02SMA | Finder 90 Relay Socket for use with 60.12 8 Pin, DIN Rail, 250V ac | RS

uk.rs-online.com

60.12.8.230.0040 | Finder Plug In Power Relay, 230V ac Coil, 10A Switching Current, DPDT | RS

uk.rs-online.com

But you get lower profile relays, etc, and if you put it is some sort of separate box (even an empty "Garage CU" DIN enclosure) it can go anywhere the is convenient.

If you only want one alarm wire the relay contacts in series so either opening will trip the alarm.

As they are DPDT you could even use the 2nd set of contacts to drive indicator lights, etc.

 

[Brando]

Just put the 230V relay coil on the RCBO output, on power fail the relay opens and you can use the contacts to tell the alarm in a suitably isolated manner. I have used the following in a Hager TPN board and it fitted (just) height-wise:

90.02SMA | Finder 90 Relay Socket for use with 60.12 8 Pin, DIN Rail, 250V ac | RS

uk.rs-online.com

60.12.8.230.0040 | Finder Plug In Power Relay, 230V ac Coil, 10A Switching Current, DPDT | RS

uk.rs-online.com

But you get lower profile relays, etc, and if you put it is some sort of separate box (even an empty "Garage CU" DIN enclosure) it can go anywhere the is convenient.

Just thought get auxiliaries contacts that clip in each rcbo wire them in series to go to alarm ,

 

[pc1966]

Just thought get auxiliaries contacts that clip in each rcbo wire them in series to go to alarm ,

If you can get them it is simpler! That would very much depend on the make of RCBO/CU as to what is available.

 

[Brando]

If you can get them it is simpler! That would very much depend on the make of RCBO/CU as to what is available.

Think that's the best way forward tbh and look better ,if inspected

 

[Zerax]

Wouldn't some sort of temperature alarm be better... so if the temp of a tank drops to a set level, it'll alarm ? This way you pick up any and all faults ? I imagine that a large tank of water will be very stable temperature wise as water has a very high 'specific heat capacity'... so even a 0.5ºC temp drop could be picked up ?

Surely this has all been done before ? There must be a 'standard' solution already out there ?

 

[Brando]

Wouldn't some sort of temperature alarm be better... so if the temp of a tank drops to a set level, it'll alarm ? This way you pick up any and all faults ? I imagine that a large tank of water will be very stable temperature wise as water has a very high 'specific heat capacity'... so even a 0.5ºC temp drop could be picked up ?

Surely this has all been done before ? There must be a 'standard' solution already out there ?

Can't find a standard solution ,I put sockets on 3 or four radials, then put rcbos with auxiliary contacts on the side so if they trip it will activate a security alarm or alert, then a back up air curtain in the room to keep air temp up as this is the case now

 

[Moley]

Wouldn't some sort of temperature alarm be better... so if the temp of a tank drops to a set level, it'll alarm ? This way you pick up any and all faults ?

I assume with 20 heaters we are talking multiple tanks. With talk of 2 per tank that's 10 tanks (I know, without even using a calculator!) So, I guess monitoring the temp of each tank would be more complicated and expensive than just two relays monitoring the supply. Temp monitoring would show up individual heater failure but I find the heaters are pretty reliable. I think I've had one, maybe two fail in all the years I've kept fish. Main reason to replace a heater I find is the outer cable hardens where it's under water and cracks.

 

[Brando]

I assume with 20 heaters we are talking multiple tanks. With talk of 2 per tank that's 10 tanks (I know, without even using a calculator!) So, I guess monitoring the temp of each tank would be more complicated and expensive than just two relays monitoring the supply. Temp monitoring would show up individual heater failure but I find the heaters are pretty reliable. I think I've had one, maybe two fail in all the years I've kept fish. Main reason to replace a heater I find is the outer cable hardens where it's under water and cracks.

There may be more tanks just looking at possible install methods and simple controls over the electrical components the tank temperatures i assuming the client will monitor supervise?? First time I been called to do such an install im only a simple sparkey