Timer in Power line.

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driver0606

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Hello,
I have a 24v toilet pump with a vacuum switch on the pump. Occasionally the vacuum is too low and the pump does not automatically switch of after about one minute as it should. I want to put a timer in the line to the pump, so when power is supplied, if the power is not turned off after, say one minute by the pump's vacuum switch, it will be turned off after the time delay set in the timer, say two minutes. There will then be no further power drain. Normally the vacuum switch will turn automatically within about one minute and the timer will not be activated.
If that all make sense, does anybody know where I might find such a switch, please?
 
driver0606 said:
Hello,
I have a 24v toilet pump with a vacuum switch on the pump. Occasionally the vacuum is too low and the pump does not automatically switch of after about one minute as it should. I want to put a timer in the line to the pump, so when power is supplied, if the power is not turned off after, say one minute by the pump's vacuum switch, it will be turned off after the time delay set in the timer, say two minutes. There will then be no further power drain. Normally the vacuum switch will turn automatically within about one minute and the timer will not be activated.
If that all make sense, does anybody know where I might find such a switch, please?
Click to expand...

Such units are "off the shelf". They have names made up of relay, time delay, resettable, retriggerable.... and the like.
You need to decide what happens in ALL cases, such as what happens when the pump (rightly) needs to start again within the timeout that the relay is counting down from the last operation..
Without going into detail this http://www.12voltplanet.co.uk/adjustable-delay-timer-relay-delay-on-or-off-24v-10a.html might be what you want.
 
driver0606 said:
Hello,
I have a 24v toilet pump with a vacuum switch on the pump. Occasionally the vacuum is too low and the pump does not automatically switch of after about one minute as it should. I want to put a timer in the line to the pump, so when power is supplied, if the power is not turned off after, say one minute by the pump's vacuum switch, it will be turned off after the time delay set in the timer, say two minutes. There will then be no further power drain. Normally the vacuum switch will turn automatically within about one minute and the timer will not be activated.
If that all make sense, does anybody know where I might find such a switch, please?
Click to expand...
Is there anything that needs fixing on your vacuflush? Putting a secondary switch in does not feel right to me. Occasionally our vac keeps pumping, at which point I will find one of the heads empty of water. A quick brush around generally dislodges whatever is causing the water to drain, and all back to normal.
 
I have had loads of problems with vacuflush toilets.
The problem you outline is just one of the issues.
Be careful - the pump running on is more likely to be a leak in the vacuum system - duck bills leaking etc.
I've also changed vacuum switches before to cure the problem that you outline.

Also, the converse can happen which is more drastic - the switch sticks in the open position and won't trigger the pump at all.

IMO, the proper solution is to strip the whole assembly down and replace necessary components (duck bills particularly).

I've actually got to the end of my tether with vacuum toilets.
This winter we would have needed at least a new vac generator unit - probably two - list prices around £800 or £900.

So, I've chosen to replace the vacuflush system completely.
Three new Planus toilets arrived here in Spain last week.
A complete new Planus toilet was less than the cost of a new vac generator.
So, once fitted (probably sometime in November) , I think this replacement option will be cheaper than repairs to the old vac system
 
Many thanks for all of your replies and advice.
The water very occasionally leaks slowly out of the toilet seal, breaking the vacuum, despite all of the components being new. A soft brush around normally cures it, but of course, if this happens unnoticed, the pump could be running for ages.
I prefer to not have the hassle of changing the system, especially if a switch in the power line is a simple solution. The switch mentioned in the first reply will not quite do but I have found this on e bay-

http://www.ebay.co.uk/itm/DC-24V-Mu...899151?hash=item210b34528f:g:inUAAOSwYGFUs0c9

I cannot be sure from the spec if it will do the job, but its cheap enough to give it a test.
 
driver0606 said:
I prefer to not have the hassle of changing the system, especially if a switch in the power line is a simple solution. The switch mentioned in the first reply will not quite do but I have found this on e bay-

http://www.ebay.co.uk/itm/DC-24V-Mu...899151?hash=item210b34528f:g:inUAAOSwYGFUs0c9

I cannot be sure from the spec if it will do the job, but its cheap enough to give it a test.
Click to expand...

Lets start with your eBay one is a fraction of the cost.. so a winner from the start.
But...

The one I linked to will do the job (its just not quite so obvious, relays are like that)
wire signal from switch to common/load power contact (pin 30)
wire N/C switch out (pin 87a) to input signal (pin 15)
wire N/O switch out (pin 87) to motor
wire earth/ground (pin 31) to system 0V

That way you change the continuous motor run signal to a momentary trigger.
 
Many thanks for that, it covers the point about requiring a momentary trigger.

I was away from school when they did electricity and I never caught up, so does this mean the following, please?

Connect + supply from vacuum switch to pin 30
Join pin 87a to pin 15
Wire pin 87 to pump motor +
Wire pin 31 to earth -

The pump load is less than 10a although I am not sure if there is a higher momentary start load. The fuse is 10a.

I would certainly be more comfortable with this relay than the cheap Chinese widget.
 
driver0606 said:
Many thanks for that, it covers the point about requiring a momentary trigger.

I was away from school when they did electricity and I never caught up, so does this mean the following, please?

Connect + supply from vacuum switch to pin 30
Join pin 87a to pin 15
Wire pin 87 to pump motor +
Wire pin 31 to earth -

The pump load is less than 10a although I am not sure if there is a higher momentary start load. The fuse is 10a.

I would certainly be more comfortable with this relay than the cheap Chinese widget.
Click to expand...

Your connections are right. Start up will be fine, relay contacts are rated at what they can take continuously and what they can disconnect, both of which are in spec. A brief, not excessive over current wont hurt a bit. Its usually a good idea to add a capacitor across a motor (might well be one there already). It preserves switch/relay contacts from arcing on disconnect and also reduces interference.
 
Oh dear. When I called to order the relay, the nice chap at the store said although the timer would start OK, when the time ended and the power was cut, it would re cycle and there would be a continual loop. If this is not too boring, do you agree, Please?
 
driver0606 said:
Oh dear. When I called to order the relay, the nice chap at the store said although the timer would start OK, when the time ended and the power was cut, it would re cycle and there would be a continual loop. If this is not too boring, do you agree, Please?
Click to expand...

Gahh, my bad. He is right.
What you want is (apparently) called an interval power on relay. It does exactly what you need, a timed closed contact from when power is applied. The contacts open when either the power is removed (vacuum switch working properly) or after the preset time (switch sticking on)
Trouble is I cant (easily) find one.
 
Dougal Tolan said:
Gahh, my bad. He is right.
What you want is (apparently) called an interval power on relay. It does exactly what you need, a timed closed contact from when power is applied. The contacts open when either the power is removed (vacuum switch working properly) or after the preset time (switch sticking on)
Trouble is I cant (easily) find one.
Click to expand...

I have a Squadron 58 and the first thing i did was to rip out the Vacuflush which in the words of JFM are the work of the devil. He is right.

A friend has a T47 and they have perpetual grief ( the good news being they have 2 WCs so one normally works).

I know others suggested it and I am not trying to be a smart arse but to be frank they are terrible things with far more parts than they need to simply flush a WC. Vacuum units, duck valves, foot pedals, wc seals and so on.

You can repair them properly, try to do something with a timer, or rip them out and be done with it.

The issue with a timer will be that they are clearly leaking or the pump would not run on. Hence when you try and flush there will be no vacuum so a poo and paper will just drop through. You need the vacuum to flush. We used to turn them off at the helm for the night and then on again, but the timer will not do the same thing.

You also I assume want to stop the damn things running in the middle of the night, and if you succeed on the timer it will still (I assume) run for a minute in the night and wake everyone up.

They were sold as a premium WC and having had them cannot possibly understand how the buyers and boat builders fell for such a trick.

I bought my WCs from Coastal Rides. Tecma are good, but there are plenty of cheaper ones that will be far far better than vacuflush.

Jeremy
 
Agree with jrudge.
On our generation of Princess, they fitted local switches in each bathroom which feed the vacuum pumps/generators.
I can't imaging the hassle if these switches didn't exist!!

However, looking back at post #6, you say that the water gradually drains from the toilet pan.
I had one that did this and the solution was easy.
There is a metal clamp (rather like a huge jubilee clip) that clamps the porcelain to the lower flange.
You need to do this up really tight - I used a big square shaft screwdriver and a spanner to get it really tight.
Doing this clamps the toilet tightly down onto the rubber flange gaskets and stopped the leaking.
Replacing the parts would also eventually fix the problem - the rubber seal and perhaps the ball/valve that rotates with the foot lever.

As I said though - these vac systems are a huge amount of trouble.
Replacement seems to me to be the best solution.
I haven't actually replaced mine yet but I've just got back from a couple of weeks away with the family.
Our main cabin system was working fine but the other two needed to be switched off when not in use.
I can't wait to get rid of them (the toilets that is - not the family!!).
 
Yep to all that Hurricane and jrudge say above. Sealand Vacuflush loos are the work of the devil imho. I tolerated them for a few years on a new Sq58, back in 2004, but then discovered Tecma You are much better biting the bullet and swapping the whole thing for a Planus or Tecma which are streets ahead of any alternative. Both Italian designed and made.

If you really want to keep the vacu-jobs, I would not fit the timer switch you are contemplating. If you do, someone will use the loo, flush it, and there will be insufficient vacuum. What a mess. You're better curing the vacuum leak. To do that you have to check all joints and seals, niiiice, and leave a small puddle of water in the loo all the time. You might need new vac switches. all as described above. Builders normally put the vac units in a place that is hard to get to. This is no fun and complete false economy imho
 
While the knives are flying :cool:
They ( vacuflush ) are as described by JFM , and we had the same woes with the Sunseeker.
The hiss n pump starting at all hrs , I would clean the ball in the pot and vasalene the rubber ring .
Current boat has tecma so bliss , with a bidet function built in - but let's not go into too much detail on that bit :)
How ever what a difference ease of use etc .
Whole system inc holding tank , gauge , control streets ahead .

Funny isn't, when changing boats it was - vacuflush that one of the things on a list I did not want .
The list of "did not want " was longer than " want " list 2nd time around .
E.g. Cream 100 % wool carpets
High gloss cherry ---------- etc ---------- etc

€ 1000 for major service for one vacufush by Sunseeker ,on a Sunday after reporting fault -- same as Op *on Sat pm -- they did then a 24 hr toilet call out --- think charter clients etc
Remove the stairs , remove the vac motor , clean + replace the duck bills , replace the rubber wear in the bog .re-fit it all -- mostly labour 2 blokes @ 70 odd € / hr . Oh let's no forget TVA on top !

* the pump just kept starting every few mins and running for ever -- just got worse -despite my " fix " ^^^
 
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Wow! I had no idea so many people had problems. Thanks for all the advice. However, being an eternal optimist and not having had many problems in 4 years AND the existing installation is very tight AND I hate changing things that always seems to throw up secondary effects in the form of problems, I will persevere a little longer and look for an interval power on relay. Thanks for trying Dougal Tolan, I will do some research and if you think of any leads, please let know.
 
driver0606 said:
Wow! I had no idea so many people had problems. Thanks for all the advice. However, being an eternal optimist and not having had many problems in 4 years AND the existing installation is very tight AND I hate changing things that always seems to throw up secondary effects in the form of problems, I will persevere a little longer and look for an interval power on relay. Thanks for trying Dougal Tolan, I will do some research and if you think of any leads, please let know.
Click to expand...

As I said above, I suggest that you first have a look at the flange strap under the toilet that connects the porcelain to the bottom workings of the toilet.
Tightening it might solve your problem and costs nothing to check.
Assuming yours is like ours, that would be parts labelled "3" in the following exploded diagram.

508-diagram.jpg
 
driver0606 said:
Wow! I had no idea so many people had problems. Thanks for all the advice. However, being an eternal optimist and not having had many problems in 4 years AND the existing installation is very tight AND I hate changing things that always seems to throw up secondary effects in the form of problems, I will persevere a little longer and look for an interval power on relay. Thanks for trying Dougal Tolan, I will do some research and if you think of any leads, please let know.
Click to expand...

If I understand correctly you actually need one of these:-

http://www.ebay.co.uk/itm/DC-5V-12V...hash=item3ae6b3f9fe:m:mNB8XqeeqL8F4cHAC_y5TDA

This should only cycle once per power on.
 
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