Frequently Asked Questions

Unlikely.  When the dimmer is placed in auto mode, the display window becomes a DC volt meter. So, “-.-“ is a reading of ZERO volts.  That means one of three things:

The controller is not sending any DC analog volts.  You need to verify the output from the controller to make sure it is doing what it is programmed to do.

The small black and small red wires that connect from the dimmer to the DC analog output may be connected incorrectly. Typically, we find about 15% of all controllers have the polarity swapped at the DC output. Switch the red and black wires.

It is unlikely, but possible, the dimmer may be the culprit. If you cannot find an answer in the above two options or if you do not have a 0-10v DC analog meter, take a 9v battery that you know is good – like from your transistor radio – connect it to the small red and black wires coming out of the dimmer.  You should see a number in the dimmer display showing the strength of the battery.  If you do not, switch the polarity. If, at this point, you still only see “-.-“ you may have a dimmer hardware issue. Call us for Tech Support 800-737-1837.

No.  Not at all.  There is a great lack of knowledge among people who just resell imported bulbs as to how those bulbs operate and what makes them dim.  LED bulbs produce Total Harmonic Distortions (THD), because each one is its own little machine.  Those THDs are no big deal when you have 4 or 5 in your home (almost all LED bulbs being used in poultry are just household bulbs being sold as agriculture bulbs), but when you put 50, or 70, or 100 + in a poultry house, the THDs are massive.  These distortions produced by the bulbs affect the bulbs, themselves.  That is, the bulbs interfere with each other.  Those same distortions also interfere with other equipment.  You typically wouldn’t see the effects the interference caused on something like a feed motor.  However, you would easily see the effects on LED bulbs or a non-LED dimmer. The distortions created by the large number of LEDs can affect (but not harm) a non-LED dimmer, but the dimmer – even a non-LED dimmer – does not affect or harm the LED bulbs.

Heat and poor components.  As long as the LED importers continue to lessen the quality of the LED components and remove the heatsink, LEDs will fail prematurely. Our research confirms this finding. You can see results on our website.

Heat and poor components.  As long as the LED importers continue to lessen the quality of the LED components and remove the heatsink, LEDs will fail prematurely. Our research confirms this finding. You can see results on our website.

No. But, the Precision Lighting MR4 dimmer can fix that. The engineers designing LED bulbs consider this issue to be normal and not a problem.  It never occurs to those engineers that anyone would install these household bulbs by the multiple dozens on the same circuit.  They also would never understand why anyone would dim that household bulb 95% to 98% and keep it that low for 18+ hours a day and then try to turn them back on at that low level. From their point of view (your living room, for example), who would do this? They expect you to dim your LED down 50%, or so, while you are reading, before bed. When you turn it back on, it’s at 50%, so it works fine. LEDs have two important voltage markers:

Minimum Voltage to Maintain (MVM) – this is how the bulb is designed. It is a machine and requires fuel (volts) to operate. If you run your car gas tank down to fumes, your car will sputter and then die. Same here. LEDs need fuel. Some need more than others, so some MVM levels are lower than others. The MVM is the least amount of energy at which this bulb can stay on;   

Threshold Voltage (TV) – LED bulbs have to recharge their capacitors before they can properly restart. This requires a higher level of energy than it uses to simply maintain at a low level. Bringing the voltage up restarts the LED, at which point dimming can resume. The MR4 allows you to produce the ideal ‘restart’ level and duration. All models of the PLS MR4 2400 LED dimmers are made to easily allow the end user to adjust this needed restart level (we call this, The Kicker). MR4 models v9.25p and higher have a default Kicker programmed in.  The Kicker will restart your bulbs, then drop back down to your preferred dim level. You may delete The Kicker or edit it to your needs.  It is simple to do.  Please see the Precision Lighting Systems, Inc. Uses Manual for The PLS MR4 2400 LED Dimmer.

The dimmer cannot cause this issue. You have a wiring connection, keyless socket, or lamp problem.  The dimmer has one line of power going to the front half of the barn and a second line of power going to the back half of the barn. It is not connected to individual bulbs. For example, in row 1, if the first 4 bulbs are on, then the next two are not, you do not have a dimmer issue. If you are qualified to evaluate and repair electrical systems, check the wiring at the keyless sockets. Don’t forget that it may just be a couple of failed or weak bulbs, which is often the case with inexpensive LEDs.

These are warning codes.  Each, although similar, indicate very different issues.

On the input side - where the 120v AC power leaves the panel box and connect to the dimmer – is called the Line Side.

The output side – where two legs of 120v AC power leave the dimmer to go to your bulbs – is called the Load Side.    

“Sh” indicates there is a probable issue on the Line Side, that is, how the dimmer was wired up. Wiring should be:

•  Green from the dimmer connects to the Ground Bar at the panel box.

•  White from the dimmer is dedicated and connects to the Neutral Bar.

•  Solid Blue from the dimmer connects to a 120v 20-amp breaker.

•  Black and White Striped from the dimmer connects to A Side Load.

•  Blue and White Striped from dimmer connects to B Side Load.

•  Small Red/Small Black wires connect to 0-10v DC Analog output of controller. If not using 0-10v, cap these off.

“SH” indicates there is a probable issue on the Load Side, that is, your sockets, bulbs, and Load Side house wiring.  Most common problems:

Keyless (or other style) sockets: There is a reason many sockets are relatively inexpensive.   Most are not exactly built with quality and long-term use in mind. Even a new keyless socket with a damaged screw shell will be problematic. Your bulb may make contact the tab in the socket, so it will light up. However, any movement (fans, etc.) will result in amps produced that mimic a dead short. The dimmer will protect itself, in that case.

Bulbs: Truth is, all of these household bulbs being used in poultry and agriculture are actually rated for 3 hours a day usage. When used 18+ hours a day, you are using 6+ days of life out of that rating. These bulbs age, and do so rather quickly. The poorer quality components that are currently being used simply add to the problems. As they age, sometimes, one or two bulbs will begin to arc on the inside. You don’t always notice it, at first. That arcing is the same pattern as crossing two live wires. 

These bulbs also produce an incredible amount of inrush current. Inrush current occurs not only when you first turn on the bulbs, but 60 times a second the entire time the bulbs are energized. You may read 7 or 8 operating amps on each line going to the dimmer. What you cannot read with an amp meter is the inrush current. On our oscilloscopes – depending on which brand bulb, watt, and number of bulbs – we see 1,000 to 4,000 inrush amps produced by the LED bulbs that hit the dimmer 60 times a second. The dimmer is built to withstand such abuse, but it will warn you with the “SH” when the amps are getting to a potentially damaging state. Have your installer or electrician call us to help adapt the dimmer to this problem.