# Wiring to control a lift

Joined Jul 13, 2021
24
Hi All,
I am new to this forum.
I have retired from building and am in the process of building a lift in my home. I am using an electric hoist as the main lifting device.
I needed to replace the hand controller that it came with. I needed 3 control stations. I designed and built a 12/220 relay system that did this.
I am now ugrading this design to incorporate more safety features.
I want to close the 12v transformer when the lift is not in use. I have designed a capacitor in the circuit (see attached)
Will this work and how big a 12volt capacitor will I need.

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Joined Jul 18, 2013
23,938
What makes you think you need a capacitor at all?

Joined Jan 15, 2015
6,220
Lift or dumbwaiter? Here in the US we have an elevator but across the pond in Great Britain they call what I call an elevator a lift. One carries people and one carries freight such as food or non human items.

As to the capacitor I also see no reason for one. Your DC is only operating relay coils.

Ron

Joined Jul 18, 2013
23,938
Don't forget the E-Stop P.B/Relay, cuts power immediately.

#### shortbus

Joined Sep 30, 2009
8,966
Don't forget the E-Stop
I thought that was the ground floor of the shaft was for?

Joined Jul 13, 2021
24
What makes you think you need a capacitor at all?
I need a capacitor because the transformer wont have any 220 volt power to run it until the relay switches (on demand)
The relay will be initially switched on demand with the capacitor, then the system should continue while 12 volt demand is there (from operating a control switch). Thats my aim

Joined Jul 13, 2021
24
Lift or dumbwaiter? Here in the US we have an elevator but across the pond in Great Britain they call what I call an elevator a lift. One carries people and one carries freight such as food or non human items.

As to the capacitor I also see no reason for one. Your DC is only operating relay coils.

Ron
I am trying to have the transformer off ( no 220 volt power to it until required) I dont want it on 24/7.
As an Aussie we call it a lift/elevator. a hoist carries goods.

Joined Jan 15, 2015
6,220
Well OK then. You can switch the transformer On or Off and only On when there is demand. You still do not need a capacitor. Just include limit switches to prevent overtravel of the hoist motor. Since you are running on 12 VDC you can include or omit a battery backup just in case power fails between floors but since this is only for goods and not moving people that is your choice. No clue as to Australia but would assume when you start moving people new safety rules apply, moving just goods not so much. Anyway, I see no need for a capacitor as you don't need filtered DC to run a hoist motor on 12 VDC.

Ron

Joined Jul 18, 2013
23,938
I somehow sense you are thinking the capacitor is going to be some standby power for a period, if so, the size value you would need would be enormous and not practical.

Joined Jul 13, 2021
24
Well OK then. You can switch the transformer On or Off and only On when there is demand. You still do not need a capacitor. Just include limit switches to prevent overtravel of the hoist motor. Since you are running on 12 VDC you can include or omit a battery backup just in case power fails between floors but since this is only for goods and not moving people that is your choice. No clue as to Australia but would assume when you start moving people new safety rules apply, moving just goods not so much. Anyway, I see no need for a capacitor as you don't need filtered DC to run a hoist motor on 12 VDC.

Ron
I have already included travel limit switches in the system. I am running 12 volt on the switching side only. this then operates the 220 volt switch for the 220 VAC hoist motor (forward & reverse induction)
I figured out that I have designed a starting sytem but not a system to close the supply of 220/12 volt power when finished.
Please see the attached new diagram. I have incorporated 12volt timers so the system (transformer) shuts down after a period of time.
Remember my goal is to not have the 240/12volt transformer running 24/7 - only on demand.

I could change the system and delete the transformer and use a 12 volt battery, then I would have to incorporate a 12v charger to keep the battery charged.

PS I am retired in Thailand.

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#### LowQCab

Joined Nov 6, 2012
1,343
There's a much easier way to do this .................
The Batteries will last ~5-years or more.

The only expensive parts are the High-Voltage Solid-State-Relays, (SSRs)
You will probably need 4, at around ~$40.oo each. If you will provide the wiring Schematic for your Motor, and the Current-Ratings, I'll give You the numbers that You need. . . . #### shortbus Joined Sep 30, 2009 8,966 Remember my goal is to not have the 240/12volt transformer running 24/7 - only on demand. What do you think that will save in electricity? With no load on a transformer the energy use is minimal. With no load on the transformer the only energy used is to keep the core magnetized. Thread Starter #### Mantadive Joined Jul 13, 2021 24 What do you think that will save in electricity? With no load on a transformer the energy use is minimal. With no load on the transformer the only energy used is to keep the core magnetized. Shortbus: Not really worried about energy, but probably long term use always on just doent seem right. Thread Starter #### Mantadive Joined Jul 13, 2021 24 I somehow sense you are thinking the capacitor is going to be some standby power for a period, if so, the size value you would need would be enormous and not practical. Yes that was my thinking - I am not very knowledgeable in electronics. I'm afraid. My field was / is designing and building houses. I guess the circuit I designed is rather clunky, but I just followed logic. Thread Starter #### Mantadive Joined Jul 13, 2021 24 There's a much easier way to do this ................. This Circuit is Powered by 4- Standard D-Cell Alkaline-Batteries. The Batteries will last ~5-years or more. The only expensive parts are the High-Voltage Solid-State-Relays, (SSRs) You will probably need 4, at around ~$40.oo each.

If you will provide the wiring Schematic for your Motor, and the Current-Ratings,
I'll give You the numbers that You need.
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View attachment 243457
Wow: Thanks for the design, a lot of effort. I have already built the 12 volt system. I had an issue with the first version I had built. a couple of my friends deciced to push the up & down buttons similtaniously. It burnt out a couple of relays. In this new design I have used relays so that each side is disconnected when the other side is in use (I hope). I know my system is clunky, however as I said previously, I am a house builder and know f. a. about electronics.
I will send you the info along with some pics. Once again thanks for the design.

Joined Jul 13, 2021
24
I finally finished the wiring as per my diagram. I made a couple of small amendments - running an earth to the lift housing as the system wouldnt earth thru the hoist cable successfully.

Pushed the buttons and the hoist motor runs. BUT only one way regardless of whether I push the up or down button.
I am thinking that there must be some damage to the motor wiring.
Originally the hoist was working great, up / down no issues. Then a couple of mates came over and decided to operate both up & down at the same time. ever since then it will only unwind.

Hence the new wiring that isolates the up & down buttons from each other during operation.

Looks like a new hoist coming up. they are not that expensive here approx 8500 Baht.

Joined Jul 18, 2013
23,938
Did you use a reversing contactor with electrical and mechanical interlock functions?

#### shortbus

Joined Sep 30, 2009
8,966
Shortbus:
Not really worried about energy, but probably long term use always on just doent seem right.
So do you unplug any of your "wall wart" power supplies when what they are powering isn't in use? Or you TV that uses a remote? Anything that operates on the mains but also uses a remote control is turned on/powered up waiting to be used.

What if your on the second floor and decide you want to call the lift? But your power supply for the controller is on the first floor?

It is your choice but doesn't make much sense to me.

Joined Jul 13, 2021
24
Did you use a reversing contactor with electrical and mechanical interlock functions?
The hoist unit itself has the forward reverse function. I just copied the switch pairings in my setup. My setup was built to provide 3 control points. Upstairs downstairs and in the lift. The use of the 12volt system with relays just replicates the original wired hand control. (I was more confident using a 12v switching system with relays than a 220 volt system)
Now that the wiring system is operational again (previously it was working before the incident) the hoist motor is slow to run and runs mainly one way regardless of the up or down button being pushed, though it did run in reverse a couple of times.
So I will replace the capacitors in the hoist motor circuit. Apart from that I will double check the final pairings of wires in the circuit I made. If all that fails then I will replace the hoist unit with a new one.
Regards