Need Some Advice

[offset]

I have a bore hole pump connected to a control unit which keeps cutting out mostly in the evening I have done a couple of voltage checks and find the with the pump running I get about 210 volts to the supply connections but if I turn one of the air con units on it drops to 200v and if I run some hot water (kw heater) the voltage drops to 177v all the time the amps being drawn increase which cuts out the pump what I need to confirm is if it is a supply problem or an in house problem

[Crossy]

It certainly looks like a supply issue. Are you checking the voltage where the supply enters the house? If you can access, also check the voltage at the meter.

What size meter do you have (5/15, 15/45, 30/100)?

How far from the meter is your house?

Can you check the size of the cables from your meter to the house.

[setbkk]

It certainly looks like a supply issue. Are you checking the voltage where the supply enters the house?

What size meter do you have (5/15, 15/45, 30/100)?

How far from the meter is your house?

Can you check the size of the cables from your meter to the house.

[InterestedObserver]

Yup, if safely possible recheck the voltage at your electric meter. If low at that point it is a utility issue, provided you have a large enough meter (service).

[offset]

It certainly looks like a supply issue. Are you checking the voltage where the supply enters the house? If you can access, also check the voltage at the meter.

What size meter do you have (5/15, 15/45, 30/100)?

How far from the meter is your house?

Can you check the size of the cables from your meter to the house.

I have a 30amp supply and the meter is in front of the house about 20 meters from the consumer board I cannot check from the meter because it has a seal on it the wires to the meter are each 35sq/mm

[Crossy]

I have a 30amp supply and the meter is in front of the house about 20 meters from the consumer board I cannot check from the meter because it has a seal on it the wires to the meter are each 35sq/mm

OK, check at your consumer unit then (or an outlet near it).

Is that a 30/100 supply you have? (says on the meter) or what is the rating of your incoming breaker?

35mm cable, do you know if it's copper or aluminium?

Rating of the water heater, aircons?

[offset]

I have a 30amp supply and the meter is in front of the house about 20 meters from the consumer board I cannot check from the meter because it has a seal on it the wires to the meter are each 35sq/mm

OK, check at your consumer unit then (or an outlet near it).

Is that a 30/100 supply you have? (says on the meter) or what is the rating of your incoming breaker?

35mm cable, do you know if it's copper or aluminium?

Rating of the water heater, air cons?

The water heater that is causing the problems is if I remember correctly 8 kw and the air con is 10 amp inverter the bore pump according to the control box draws 11amp at 200v with the bore pump and the air con running I am getting 207v at the meter I cannot see the end of the cables to see if it is copper or Ali is there any wording on the cable that would tell me what the cable is made of the meter states that it is 30/100amp I will have to wait till later to use the hot water heater to see how much it drops the voltage (need to water plants at the moment

[Crossy]

If your 10A air and 11A pump are pulling you down to 207V on a 100A supply you (or rather the supply company) have a problem.

Adding another 8kW (36A) is only going to compound the issues

Can you estimate how far you are from the supply transformer?

Time to talk to PEA.

Can you use the pump in the morning to even out the load?

[offset]

If your 10A air and 11A pump are pulling you down to 207V on a 100A supply you (or rather the supply company) have a problem.

Adding another 8kW (36A) is only going to compound the issues

Can you estimate how far you are from the supply transformer?

Time to talk to PEA.

Can you use the pump in the morning to even out the load?

Thanks for your help so far no I do not know where the transformer is at the moment we already use the pump mornings and evenings what I am most concerned about if like yesterday when I turned on the water the voltage dropped to 177v and that was after it cut out the pump so that was only the water heater and one air con unit I would hate to think what might happen if I also turned on the larger air con unit as well

[offset]

Just checked with the pump off and the air con and water heater on the voltage dropped to 186v with everything turned of I got 210v also I forgot to mention that we are at the end of the line as far as the supply is concerned

[InterestedObserver]

Just checked with the pump off and the air con and water heater on the voltage dropped to 186v with everything turned of I got 210v also I forgot to mention that we are at the end of the line as far as the supply is concerned

Your utility service is obviously not able to support the load at your house. Is 3-phase service available on the pole where you get your power from the utility, or close by? With 3-phase you could split up the separate loads.

Edited April 11, 2010 by InterestedObserver

[offset]

Just checked with the pump off and the air con and water heater on the voltage dropped to 186v with everything turned of I got 210v also I forgot to mention that we are at the end of the line as far as the supply is concerned

Your utility service is obviously not able to support the load at your house. Is 3-phase service available on the pole where you get your power from the utility, or close by? With 3-phase you could split up the separate loads.

No there is no 3 phase the nearest is about 1 kilometre away in a different direction from where my supply comes from which means there are no poles to support the cables

[InterestedObserver]

The utility approved the installation of the 30/100 amp meter and corresponding service. Ask them politely how they propose to fix the low voltage problem you are experiencing. It is after all their problem.

[offset]

I managed to get to the PEA today spoke to the manager with my lady trying to translate he at first tried to show me what the problem by drawing me a sketch I told him that I knew what the problem was it was the transformer was to small or to far away he nodded and said the Government would not let him change it I suggested that it was his problem not mine (although it is my problem) I did explain that on Sunday the voltage was down to 180v with only the air con on I told him that he told us that we required a 30amp supply and I suggested he supply the power so I could use it I then showed him my electric bill which was 3800B (he is going to get somebody to check the meter because he thinks it is a bit high) I told him that I use a 10amp inverter air con all day and a water bore pump I cannot use any other large use appliances because it pulled down the voltage to much

I wonder if anybody can tell me if the voltage is low making me draw more amps would that increase the units that I use so increase the cost of the electric bill

[david96]

One of the biggest problems in Thailand is before connecting an electrical installation it should be determined by the PEA/MEA if they can supply your proposed or existing load. If not they should advise you and when an upgrade will eventuate. You should supply this information on your proposed/existing load to them first.

Just supplying a 45A or 100A meter means nothing, Your load is the max demand of your electrical installation. And any distance from the main switchboard to the point of connection to the distribution from the transformer will require voltage drop calculations.

Calculate the max demand first, this will determine your meter current rating.

Then calculate the size of consumers mains to suit the max demand and voltage drop requirements. Allow about 3% in the consumers mains and 2% in the final subcircuits.

From your information supplied you have a 220V single phase supply.

The distribution transformer must be large enough to supply all consumers that are connected to it. this is the responsibility of the PEA.

[david96]

Your voltage at the main switch board may be quite ok if you reduce your load to say 15 or 20A.

Have you offered to pay some of the capital cost of upgrading the transformer, this is what the PEA may be waiting for as they appear not to have the funding in their current budget.

You would only do this as a last resort of course.

[offset]

Your voltage at the main switch board may be quite ok if you reduce your load to say 15 or 20A.

Have you offered to pay some of the capital cost of upgrading the transformer, this is what the PEA may be waiting for as they appear not to have the funding in their current budget.

You would only do this as a last resort of course.

On Sunday with just a 10amp air con working the voltage dropped to 180v I do not want to put it into their mind that I might be prepared to pay to-wards a new transformer any idea how much one would cost also being at the end of the line the more people upgrade and use more power I could be in the same position in the future with the PEA coming round with the begging bowl