What is Corn COB LED ? And it is safe to use ?

1. What is corn cob ?

A lot of people are curious on what is LED corn cob ? It is actually referring to LED corn bulbs with edison screw base twisting into the existing HID fixtures such as post top light, wall pack, high bay, low bay, shoeboxes etc. HID is abbreviation of high intensity discharge, which includes metal halide (MH), high pressure sodium (HPS) and mercury vapor (MV). As long as the LED corn bulb dimension fit the original fixture, the corn bulb can replace HID lamp.

LED corn bulb for HID fixtures

2. Are LED corn bulbs safe ?

It depends on the the quality where you get the LED corn bulb.

For safety concern, you should get certified product for your market. There are some safety certificate for electrical components or equipment in different country e.g. If you are from United States, you should get UL ETL approved corn, cETL cUL or CSA for Canada. Usually, there is UL certified label on the product. In most Euorpean countries, CE RoHS certificate is a must, unless some country has its own specific requirement, like Germany need GS or TUV, then you should get TUV or GS approved LED lights, so that safety concern can be wiped out. UL ETL CSA CE RoHS GS TUV SAA, they all have authorized labs in some specific countries to conduct test on LED products based on their safety code.

Therefore, please open your eyes widely and ask the supplier to offer the relavent certificate for your country market entry. If they don’t have it, you should be very careful to make decision to buy it.

Now the LED lights quality in China market varies, some LED factory can pass the safety code even though they don’t get the certificate yet, maybe it is because they don’t have plan to develop your market or the certificate cost is too expensive for them. While for some factories, their products cannot pass the safety code in your country so it is hard to get.

Therefore, our suggestion is to find a reliable manufacturer or supplier who can offer the safety certificate for their product. If the product you are looking for is rarely made or hardly found in market, you can try with a sample first to test its reliability. After evaluation by your own and trust its quality, you can start to order in large quantity.

3. How to choose the right corn light for your fixtures ?

To choose the right corn light, there are 5 factors to be considered

  • Safety
  • Dimension
  • Equivalency
  • Application
  • Pricing

1. Safety 

Of course, it is neccessary to buy product that pass the safety code in your country.

Another important thing to remember is that you need to figure out the corn lamp input voltage is suitable for your power line. If working under unproper volt range, the corn bulb would be burned, or lifespan could be shortened.

For 100-277V LED corn lamps, it can be work normally under

  • 120V
  • 208V
  • 220V
  • 240V
  • 277V

If your plant power line is over 277V, it is better to use 200-480V corn cobs, we offer these as well if you need.

2. Dimension 

In order to fit perfectly in original HID fixtures such as flood light, wall packs, shoebox, acorn post top, canopy fixtures, you need to check carefully if the corn LED bulb size (length) is less than fixture inside dimension. Also keep in mind the socket base type, it is medium base socket (E26/E27) or mogul base socket (E39/E40) ? You should select the right base so that you can twist into the socket.

If you already take wrong base, you can use a base converter to check if works for you.

3. Equivalency 

For old bulb replacement, you might seek LED bulbs for the same lumen output as previous lamp or brighter. You can refer to the answer to the Q6 in this article.

4. Application 

  • Do you want to use indoor or outdoor ?  ( think of IP grade protection level)
  • Is the working location damp or dry ?  ( think of IP grade protection level)
  • Do you prefer evenly soft luminaire ?  ( think of  you need a frosted or clear diffuser or not)
  • Do you need dimmable function ?  ( think of  what kind of dimmer you use already and find corn to support it)
  • Do you have special color temperature requirement for the place ? ( CCT: 3000K/4000K/5000K/6000K)

You need ask yourself questions above and then you can finally find what kind of corn suits you best.

5. Pricing 

Final decision is hard to make, after your checking price with several suppliers and comparing features carefully, I am sure you will get the best vendor.

However, don’t fall into price trap, it is better to compare price with the same/similar quality product, also taking their services and communication efficiency, warranty term/policy, handling time into account.  After all, if any light is failed in future, you need to turn to them for getting a replacement.  If their service is very bad, it is difficult to get a new one and you have to spend money to buy somewhere else.

4. Can I use the corn cobs for indoor & outdoors ?

It depends on the LED corn bulb IP grade you get.

For indoor application, if the working environment is very clean such as your residential house or commercial warehouse, IP20 is enough. However, if the place is very dusty such as indoor horse arena or barn, a more dust tight level IP40 should be used.

For outdoor application, as the corn should not be exposed to water in damp location, otherwise its internal driver would be burnt, so we need to use IP64 waterproof rated LED corn cob bulb, usually there is a cover outside over the LEDs. Therefore, high IP grade corn is more expensive than lower grade corn LEDs.

Therefore, our suggestion is to use high IP grade corns for outdoor and half outdoor(under canopy) lighting where the water (rain drops) possible enter into the corn, while using low IP grade LED corn lamp for indoor low bay or high bay lighting in order to save cost.

5. How many corn light bulbs are there in the market ?

This is a large question, every now and then, there is new stuff to be created, so I just list what I know for your reference

  • Mini corn lamps
  • Small LED corn lamps 360 degree
  • Long corn LED light bulb 360 degree ( for deep long fixture )
  • Short corn LED light bulb 360 degree (for shallow fixtures)
  • Half corn LED bulbs 180 degree ( for wall pack, shoebox, street )
  • Pyramid LED corn lamps (for canopies, high bay etc)
  • Funnel LED corn bulb  (for post top light )
  • Foldable LED corn bulb
LED corn bulb style

6. What is the equivalent of LED corn bulbs ?

Below are the LED corn light bulbs equivalent with high pressure sodium and Metal Halide

  • 5W-6W LED  = 12W-20W MH HPS
  • 7W-8W LED = 20W-30W MH HPS
  • 9W-10W LED = 30W-40W MH HPS
  • 12W-15W LED = 40W-60W MH HPS
  • 20W-27W LED = 60W-80W MH HPS
  • 30W-35W LED = 90W-100W MH HPS
  • 40W-45W LED = 120W-150W MH HPS
  • 50W-54W LED = 175W-200W MH HPS
  • 60W-65W LED = 200W-250W MH HPS
  • 70W-80W LED = 250W- 300W MH HPS
  • 100W LED = 300W-400W MH HPS
  • 120W  LED = 400W-450W MH HPS
  • 150W LED = 500W-600W MH HPS

7. Can I find dimmable LED corn lamps in the market ?

Yes, for some special location, you might need dimmable LED corn light bulb for exclosed fixtures, but it is difficult to find it in market, why is that ?

I will try to explain this to you.

Below is the universal wiring diagram for dimmable LED light bulbs, including 0-10V dimming or triac dimming.

As you can see, it often requires a dimmable driver (number 1, 2 in image) where one end is to connect to the main power  and dimmer wire, another end to connect the loads (LED). There are some resistors inside the dimmer, so that it can adjust the current in the loads (LED), that is why you can see dimming effect. The driver is usally used to convert alternative current to directive current because LED only works under DC power.

dimmable LED corn bulb wiring diagramLED corn bulb dimmable

8. What is the main LED corn bulb manufacturer in China ?

Now it is easy to find LED corn lamps supplier through internet, but for some wholesaler or distributors, in order to get a good profit margin, their effort to purchase the lowest priced product doesn’t ever stop. Therefore, here I list some China LED cornlight manufacturers

  • SNC Lighting
  • SZ Guanke
  • Chiuer Lighting
  • Romanso

9. Where can I get the best LED corn COB light at affordable price ?

Now it is easy to buy LED cornlight via many channels such as on Amazon or from other lighting retailers’ online store like Lowes, Home depot, Best Buy, Target, Costco etc.. If you are end user(such as electricians or electrical contractors) and just buy a small quantity (less than 20pcs ), you can buy from them directly, because they often have goods in stock and you can get them fast, besides, their price is reasonable, but be careful to compare quality and buy qualified product.

We as a professional supplier have witnessed that there are many sellers out there to sell non-qualified products, because these platforms doesn’t have strict entry rule on the certificate qualification, therefore, some product that doesn’t get safety certification say they have that certificate in your country. Keep in your mind, cheap stuff has its own reason behind that, you should not choose the cheapest and the highest price corn bulbs, choose the middle.

However, if you want to purchase in large quantity, you can consider to buy from China factory, this will bring you a really extraordinary saving compared to buy from Amazon or other middleman(importers or distributors) even though you don’t have experience in importing, we can handle all affairs for you including transportation, customs declaration, paying duty tax, all you need to do is just to wait and get prepared to sign the package.

10. What is the advantage of using LED corn cob lamp compared with replacing the entire fixtures ?

Here I’d like to list the pros and cons for LED corn bulbs

Pros

  • 1. very easy to install in fixtures with medium base or mogul base.
  • 2. Cheaper than entire fixture replacement, save your labor cost and fixture cost.
  • 3. High compatibility by using base adapter, convenient for socket conversion between E26/E27 and E39/E40.
  • 4. Higher lumen effiacy than CFL or halogen, HID bulb, 80% energy efficient.
  • 5. Suitable for 360 degree illumination