Cabin light flicker when water pump runs

[collinsp]

Hi Guys,

I am having an issue with the 12V LED lights in the cabin when I run the water pump they flicker. There is no issue with battery voltage and the pump is wired directly into the electrical panel on/off switch and also has a whale pressure switch located near the pump. I have checked the voltage to the lights when the pump runs and there is no drop in voltage. I'm wondering if the pump is causing some sort of frequency when operating that is effecting the cabin lights (sure I read that somewhere in the past)?

Any thoughts and suggestions would be much appreciated.

Paul

 

[Fimacca]

I find my cabin led's affect my FM radio, as does my phone charger.
What is it doing to my brain !!??@##;

 

[Boater Sam]

Could be a wire in the supply that is undersize or a poor connection and causing volt drop when the load of the pump is on. Is this a new fault or always done it?

 

[Clancy Moped]

I find my cabin led's affect my FM radio, as does my phone charger.
What is it doing to my brain !!??@##;

Are you sure FM signal is not effected by your LEDs? This was a rumour going around when cheap Chinese LEDs first appeared on the market.

 

[oldmanofthehills]

Hi Guys,

I am having an issue with the 12V LED lights in the cabin when I run the water pump they flicker. There is no issue with battery voltage and the pump is wired directly into the electrical panel on/off switch and also has a whale pressure switch located near the pump. I have checked the voltage to the lights when the pump runs and there is no drop in voltage. I'm wondering if the pump is causing some sort of frequency when operating that is effecting the cabin lights (sure I read that somewhere in the past)?

Any thoughts and suggestions would be much appreciated.

Paul

Any motor will cause small fluctuations in its connecting wires ie interference, as the motor has a commutator which makes and breaks the circuit to sequential sets of stator windings. I am surprised it is enough to affect the lamps on a different circuit but LEDs are more sensitive - have less hysteresis - than tungsten filaments which dont flicker when supplied with 50Hz AC.

Ensure both LED and pump are properly connected to the negative with very low resistance to the terminal so that any common connection between them is negated by everything being held to the voltage at the terminal and no return current goes from motor through the LEDs to the terminal instead. If that does not do it try using an anti interference shroud round the positive wire to the pump in case its radiated interference. Most radio sets come with such ferrite doughnuts.

Some of my household LEDs flicker v slightly. It may not be a solvable problem

 

[Supertramp]

Yes, mine do too.

But to complicate things they don't flicker when the bilge pump or various holding tank pumps run. And the main cabin lights and others don't flicker, only the ones in the galley area. They are all Boatlamps tubes.

I am not letting it worry me!

 

[Rappey]

Are you sure FM signal is not effected by your LEDs? This was a rumour going around when cheap Chinese LEDs first appeared on the market

Its not just a rumour. This is from the us coastguard.

Let us enlighten you about LED lighting!
Potential interference of VHF-FM Radio and AIS Reception.
The U.S. Coast Guard has received reports from crews, ship owners, inspectors and other
mariners regarding poor reception on VHF frequencies used for radiotelephone, digital selective
calling (DSC) and automatic identification systems (AIS) when in the vicinity of light emitting diode
(LED) lighting on-board ships (e.g., navigation lights, searchlights and floodlights, interior and
exterior lights, adornment).
Radio frequency interference caused by these LED
lamps were found to create potential safety hazards.
For example, the maritime rescue coordination center
in one port was unable to contact a ship involved in a
traffic separation scheme incident by VHF radio. That
ship also experienced very poor AIS reception. Other
ships in different ports have experienced degradation
of the VHF receivers, including AIS, caused by their
LED navigation lights. LED lighting installed near
VHF antennas has also shown to compound the
reception.

 

[William_H]

An LED lamp can have current limiting circuit either in the form of a simple series resistor or by a more complex but efficient switch mode control. In the latter the current is switched a t a high frequency and limited by inductance to get precise average current regardless of input voltage. (a clew might be where LED is suitable for range of voltage from 10 to 30v. It is this rapid current switching that can cause radio interference.
Now the simple (primitive) (cheap) resistive current limiting type LED is very sensitive to input voltage.
My guess is that OP has the resistive current limiting type LED lamp and thus current through the LED varies with input voltage. (to a dramatic degree) like when a load is applied to power supply. The LED diode has a non linear current to voltage rate so typically 2.5 v full brightness 2.0 v dark. Unlike an incandescent lamp which is more linear in brightness to voltage.
As said look for resistance in wiring common to both the pump and the lamp. If nothing obvious just accept the effect. ol'will

 

[PaulRainbow]

If it is due to the type of LEDs, fit a small DC-DC converter and set it to 12V out.

 

[Stemar]

If it is due to the type of LEDs, fit a small DC-DC converter and set it to 12V out.

Or change the LEDs for 8-30v supply ones.

Out of curiosity, might a ferrite in the LED supply work?

 

[Boater Sam]

Or change the LEDs for 8-30v supply ones.

Out of curiosity, might a ferrite in the LED supply work?

Neither of those will make any difference.

 

[Mister E]

If these are on different circuits then it is probably an idea to check the neutral return.

 

[Graham_Wright]

Did you check the volts with a digital meter? That woud not repspond rapidly enough to detect a flicker. You need an analogue one for that.
A water supply pump is generally an impulse device so the current load woud very with each stroke. A bilge pump is (probably) a continuous load.
I experience a flicker (not me - the lights) with the heater fuel dosing pump.

 

[littledancersadhu]

If these are on different circuits then it is probably an idea to check the neutral return.

This would be my guesse