Whats inside the Gardiner BP?

[Craigmac]

Tango 

Were you the one having problems with water supply not so long back? 

Just the saving on water by using the univalve VS resting your pole and bending down to turn the backpack off will make it a shrewd investment. People using backpacks or vans systems that do not use a univalve are few and far between. 

Time saved also adds up. 

£40 you will make over a couple of jobs, and once you are using the univalve you will wonder how you managed without it ?

 

[Marko067]

First thing I'd do if I purchased a backpack for all day everyday window cleaning, would be to re-wire it and include a 40amp auto relay.

The pumps in these BPs were not designed to be stopped and started 100+ times a day by shutting off the water supply. The pump mechanics are quite robust and will likely stand up to it but the microswitches in the built in pressure switches are prone to failure from all the electrical arching caused when the pump cycles. The 40amp relay will reduce that likelihood to virtually nil. 

I'd hazard a guess, that the majority of pump failure stories you hear about these BPs are down to this microswitch, not the mechanics, and they are very hard to find. They are not the same ones fitted to the likes of a Shurflo. They can be made to fit but it's a right faff and for the sake of less money you can fit a 40amp auto relay. You will require a little electrical knowledge or get someone with the required knowledge to do it for you.

 

[Tango]

Reading through the thread I think the guy just doesn’t want to spend £30 ? 

To a point yes, money is still a bit tight and i have plenty of electronic bits and bobs here that i need to use - 2.4GHz modules and arduino processors and relay boards for instance - perfect for a remote control - and as i already have the parts, it's not going to cost me the £30 that a univalve would.

Tango 

Were you the one having problems with water supply not so long back? 

Just the saving on water by using the univalve VS resting your pole and bending down to turn the backpack off will make it a shrewd investment.

Yes that's right however my water woes are now over and i'm back up and running. Without a doubt saving water from the BP is a big must and i've no doubt of the benefit of switching off between windows however as @Marko067 says I doubt the pump in them will take the pressure of being switched on/off so much without suddenly letting me down at some point. If i had more money coming in reliably and could afford to have a spare pump or back pack with me at all times I wouldn't be phased but at present it's a risk I can't afford so the electronic remote which saves the pump jolting to a halt under pressure seems like a better way forward for me.

 

[chelmsclean]

To a point yes, money is still a bit tight and i have plenty of electronic bits and bobs here that i need to use - 2.4GHz modules and arduino processors and relay boards for instance - perfect for a remote control - and as i already have the parts, it's not going to cost me the £30 that a univalve would.

Yes that's right however my water woes are now over and i'm back up and running. Without a doubt saving water from the BP is a big must and i've no doubt of the benefit of switching off between windows however as @Marko067 says I doubt the pump in them will take the pressure of being switched on/off so much without suddenly letting me down at some point. If i had more money coming in reliably and could afford to have a spare pump or back pack with me at all times I wouldn't be phased but at present it's a risk I can't afford so the electronic remote which saves the pump jolting to a halt under pressure seems like a better way forward for me.

1. There's no jolting to a halt, it actually turns on and off quite smoothly

2. All the time building and programming an Arduino could be used earning money

3. An Arduino on all the time will flatten the battery

4. There's more to go wrong, there's a lot to be said for simplicity

 

[Marko067]

4. There's more to go wrong, there's a lot to be said for simplicity

This is so true.

The problem with these pumps is not the pump itself, it's with the microswitch employed within the integral pressure switch. It's current rating is too low for being repeatedly operated over a short period of time and therefore the contacts burn and eventually either can't pass the current needed to operate the pump or they fuse together. I kitted out my trolley the exact same way as a BP and experienced both scenarios several times before I tried the 40amp auto relay mod recommended by a fellow window cleaner on one of the forums. It worked a treat and now I've had at least two years with the same pump and no issues. I use the trolley on a very compact round, it gets three to four days use a week, and is being used almost constantly during that time with a univalve fitted to both my poles. Very few of my jobs are more than a few metres apart so you get the idea how much use it gets, so there's no reason to expect that a BP wired the same way wouldn't last as long or longer.