Is it ok to use timer plug on inverter split outdoor unit

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Hi all. Have 4 LG indoor wall mounts connected to outdoor unit. Sick of having to reset the timers each day would it be possible to fit the outdoor a timer plug? Or will this have a detrimental affect when the timer just cuts the power to the outdoor unit when it could still be running? Currently indoor unit wired to a 13amp plug has worked fine like this for years. But no longer use the central heating as is cheaper to run the air con in heating.

I know there is a crankcase heater in the outdoor unit so if there is no power supplied this will not be running.


Thank you.

[install monkey]

u want to fit timer adapters to the indoors and a timeclock or convert the units to hard wired controllers to utilise the 7 day time clock

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How would you go about fitting timer plugs to the individual indoor units? Wouldnt this look unsightly. The cost of hard wired controllers is £70 a pop from LG I would need 4 of these so its quite expensive when I could get a digitial time clock (have spare ones) for about £5. Is it not a good idea to have the outdoor unit on a timer plug?

[install monkey]

outdoor could be on a timer but what is the size of the breaker as a timer is normally only rated for 10amp, sangamo mechanical ones are rated for 16-20amp and them mickey mouse plug in timers take a long time to switch and youll get interference on ur tv when theyre mid switching, does the outdoor have a crankcase heater? as this would still need powering during an off period otherwise your gonna have premature comp failure

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Its a 13amp breaker. But when its at max output it only ever seems to draw about 10amp. Cheapest and easiest solution is to fit a timer to the outdoor unit. Just worried if cutting power to the outdoor unit will cause wear and tear on components rather than the off command on the remote control. Not sure if it has a crankcase heater?

[jdunc2301]

if your a real handy man could run the comms through a timer...... if your lucky it wont throw up errors

[install monkey]

on a multi split, the only comms is the signal cable which breakin that will still keep the indoor fan running, maybe killing the live to each indoor via a contactor in an enclosure will stop the outdoor from running
if your a real handy man could run the comms through a timer...... if your lucky it wont throw up errors

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I know when the comms errors comes up the unit goes into error mode and turns itself off. This isnt ideal as has to be powered back on again.

[install monkey]

yep your correct, each indoor unit will be fed off the outdoor via a 4 core cable , live,neutral,signal and earth. by switching the live ( switching neutral is frowned upon in the uk) will stop the indoor and the demand, as its a multisplit if you switch all lives to each indoor then the unit should auto restart when repowered up(timeclock on) best option is to open up the outdoor and check the wiring diagram for a crankcase heater- or look at the compressor for a heater wrapped around the base(under the insulated jacket) if no heater then it would be possible to switch the condenser power

[back2space]

yep your correct, each indoor unit will be fed off the outdoor via a 4 core cable , live,neutral,signal and earth. by switching the live ( switching neutral is frowned upon in the uk) will stop the indoor and the demand, as its a multisplit if you switch all lives to each indoor then the unit should auto restart when repowered up(timeclock on) best option is to open up the outdoor and check the wiring diagram for a crankcase heater- or look at the compressor for a heater wrapped around the base(under the insulated jacket) if no heater then it would be possible to switch the condenser power

Ok managed to find the service manual that was sent to me... cant find any mention of a crankcase heater. Only page 50 mentions the startup process for compressor at low ambients...

Compressor warm up control logic: (at low temps)
A function protecting inverter compressor from damages, by increasing oil viscosity in low outdoor temperature.
For the control,compressor operates in low frequencies.
Operating condition :in case of the following 3 conditions are fulfilled at the same time
- Outdoor temperature ,D-pipe temperature, Heat sink temperature: below 0°C
10. Compressor warm-up control logic (at low temperatures)
Comp.
LEV Opening target : 0.7
0 sec.90 sec. 0 sec. 180 sec. 0 sec. 300 sec.
15Hz 15Hz 15Hz
Opening target : 0.7 Opening target : 0.7
Time (option) Time (option) Time (option)
starting
starting
starting starting
starting starting
-5°C ≤ OD temp. < 0°C -10°C ≤ OD temp. < -5°C OD temp. < -10°C

[frank]

yep your correct, each indoor unit will be fed off the outdoor via a 4 core cable , live,neutral,signal and earth. by switching the live ( switching neutral is frowned upon in the uk) will stop the indoor and the demand, as its a multisplit if you switch all lives to each indoor then the unit should auto restart when repowered up(timeclock on)
Got to be careful here if you have any condensate pumps fitted.

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No condensate pumps but to be honest in summer would just leave at constant and use the infra red remotes to control. Its just winter is a pain to control.

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Any one advise if its gonna be an issue putting the timer plug on for the outdoor unit? Will it damage anything?

[frank]

Does the unit have auto restart after power fail enabled?

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Yes it does. I also checked with LG and the outdoor doesn't have a crank case heater apparently their is a small voltage passed through compressor 18w when off. He said this isn't a crankcase heater though.

Whilst on the phone I asked about the hard wired remotes. He says you can have 2 on 2 off cycles per day. However according to the manual you can have 2 events per day, on and off. This means you can't have it coming on in the morning and then again in the evening. So @ £97 each these are expensive and won't do what is required.

My £5 digital timer from screwfix would be ideal but don't want to cause any problems with the outdoor being an inverter system.

[frank]

In that case, you could wire your timer to interrupt the live feed to each indoor unit through a 4 pole relay and have your timer operate the power to the relay coil. You could do this at the outdoor unit. This would leave power on to the compressor oil warming circuit but drop power to the indoor units.

If you leave the indoor units on in heating, they should restart every time your timer energises the relay.

Try it with 1 unit and see if it restarts OK

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My installer is coming next week to have a look for me. May look really unsightly to have timers on the walls though so hes gonna look at it for me. I think I might just buy these timers from LG then they are done properly then.

One other questions.... now were in heating season can hear vibration noises from outdoor unit at the indoor units when its ramped right up. The outdoor unit is wall mounted on brackets. The noise is not coming from the wallbrackets on the wall as the indoors are not mounted on the same external wall as the outdoor unit but the vibration is like a buzzing sound coming up the pipework.

When the unit was installed at the other house I lived at occasionaly got a slight hum but this is much louder and more annoying. Pipelengths are about the same.

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Just thought I would update you all of my progress. I decided to bite the bullet and bought the remote controllers x 4. Had a nightmare setting the weekly timers up with some days and cycles in that day not actually operating. Constantly having to reset the controllers due to intermittently running. The instructions are converted into English from non english I think and are really hard to understand and half the instructions dont follow correctly so I had to figure it out for myself. Hopefully they are working now. However to cancel the weekly timer the option doesnt work and I have to reset the controller! @ £90 a controller + VAT on top you would expect it to be perfect.