Welcome to this month’s blog – In this article, we look at warranties- their potential pitfalls and how to avoid them.
Warranties for luminaire products should at first glance, should be a simple issue – However, many warranties do not cover the product for all eventualities which may occur onsite, and some can be simply misleading!
A warrant may be conditional – and may not include coverage for an issue that can occur due to the nature of the site or application.
Q- Does the warranty include lumen maintenance?
Most warranties should include lumen maintenance – but be warned! Some warranties only cover total product failure.
This means the warranty does not cover underperformance -where the products delivered light levels have dropped below usable requirements - but the unit is still dimly working.
In such cases- unsafe lighting levels can result onsite [potentially leading to accidents and insurance claims] and the purchaser is left with the new product+ labor cost – along with a damaged reputation and a loss of future work.
Some manufacturers will state the warranty is not a guarantee of light level performance, and will simply walk away.
Some suppliers may alter the manufacturer’s original warranty conditions- reducing the warranty period and changing the conditions [such as removing a guarantee of lumen maintenance – or reducing the drivers warranty period].
Always check the conditions of the warranty – Make sure it includes/guarantees the lumen maintenance.
Warning – some warranties have provisions on running time – which are misleading!
Some warranties state a guarantee of 5 years – providing the unit is only powered up for 20,000Hrs!
In such cases – the manufacturer has a get-out clause- also bear in mind that life span will vary with onsite conditions.
There may also be clauses, restricting the number of on/off switch cycles – so a luminaire operated by occupancy sensors may fail early – leaving the customer without warranty cover!
Another point to consider is – will the supplier still be around after 50,000-Hrs, if the supplier has a long market history it may be the case- but there are plenty of fly-by night traders out there.
We saw an LED streetlight advertised on a well-known internet sales site, with the following worded warranty -
Warranty = 10 years /10,000Hrs.
There is no mention of a guarantee of long lasting light level performance!
The warranty is unclear – and can be interpreted as follows:
The warranty only covers 10,000Hrs operation time [when used over a 10-year period]
However – supposing the number of switch-start operations is exceeded in the first 5,000 hrs. [If the unit was switched from a sensor] causing the unit to fail?
What will the seller decide to do?
It is hard to see how the E bay seller can state they will honor the warranty– as there was no point of contact for the supplier!
Warranties may include additional conditions that may override other clauses-
Warranties can be voided if the products recommended Ta ratings have been exceeded – if a product has a maximum Ta of 45C and the site’s ambient temperature is 50C, the product may have a reduced light output – or fail.
When selecting a lighting product – always check the product can handle the maximum expected onsite temperature conditions - on the hottest day of the year, if the site temperatures are higher than expected, it could lead to onsite failures – with no refund from the supplier.
One potential pitfall occurs, when onsite staff [who are not lighting technicians] are asked to estimate the max, onsite temperature for the supplier, who will then check the products Ta rating – bear in mind that temperatures at ceiling height [or fixed into cavities] can be much higher than expected [the staff cannot be expected to know the ceiling height temperatures -during the hottest day of the year]
Often such data is done over the phone – so there is no record of who said what, at the time of install.
We recommend using Emails for such information requests – and to use a lighting technical to survey the site [taking max, site temperatures into consideration] the lighting technical can then apply a degree of headroom, when selecting the products – to play safe.
In such cases -where the onsite staff have guessed the max, temperature incorrectly, a debate as to who is responsible for product failure, will place the responsibility onto the supplier or installer– who will have to pay replacement costs+ labor costs!
Also bear in mind - what temperatures may occur on the hottest day of the year [sometimes there is no data available] so a survey conducted in winter may rely on hearsay.
Other factors come into play – such as changes in site conditions or routines throughout the year – as well as climate change [global warming].
We have seen some warranties claim 100,000Hrs product lifespans
As far as we know -at the moment, no one has run a high powered LED for 100,000Hrs at onsite conditions to show this is the possible onsite.
These warranties are based on LED lifespan predictions.
Many LEDs have a Max, LM80 prediction time of 42,0000Hrs and rising -at present. But one company has recently claimed 100,000 Hrs LED lifespan [based on an LM80 predictions]
This claim may be correct - for that particular LED, used at a particular drive current/temperature [we have not seen the data used for the prediction] However, there are many issues to consider regarding this statement.
1. The LED used for the 100,000Hr prediction does not represent all LEDs on the market- an assumption may be made that all LEDs predicted to perform for 50,000Hrs can actually perform to 100,000Hrs. The running temperatures and drive current, and type of start-up wave form of the completed products – will affect each units LEDs differently.
Reliability is heavily linked to good luminaire design – onsite conditions also affect the product life span.
2. Competitors may copy this claim, on the basis that they are using the same make/model of LED – but the LED could be running at a higher temperature and current –when inside the competitor’s product. This raises concern that the market will be flooded with false claims – making it hard to discern, which product has such abilities.
Bear in mind- there is a difference between LED reliability and product reliability, a product is only as good as its weakest link!
There are many variables involved in product reliability such as:
1. on/off switch cycle limits – or surge/spike handling v degree of repetition/level/ of voltage spikes onsite]
2. The lifespan of the heatsink paste [used to shift heat from the LED board to the heatsink]
3. If the luminaire is working outside [in the rain] - will the sealing gaskets last for 100,000hrs?
4. If metal corrosion occurs- the mountings and seals may be compromised.
5. Repetitive thermal expansion/contraction effects – may eventually create a gap between the LED board and the heatsink [leading to overheating]
6. Long term exposure to gases [such as Sulphur dioxide from cars- chlorine from swimming pools – which can damage LEDs – it may be hard to predict, what gas levels occur on a street ,or site over 11 years – or what level of gas exposure would occur over that period.
7. Long term dust build up – dust can be coating the heatsink /driver – reducing the product lifespan.
8. The driver may not be rated to last for 100,000hrs. We note some drivers can be ran at a reduced wattage and run cooler – some Meanwell drivers are capable of running for 100,000Hrs [if running at lower temperatures and kept clean] However-this would mean running a 200W driver at a lower wattage [this increases product cost]
9. If the paint work will still be UV resistant – and not peeled off [street lights with peeling paint and rust may look unsightly] also consider – if the paint has peeled, UV rays from sunlight may no longer be reflected off during hot sunny days, this could cook the internal capacitors – leading to a reduced lifespan [even when not powered up]
Peeled off paint could also expose micro-pitted metal work on the heatsinks– with could fill with dirt/dust [leading to overheating]
We believe a recognized test standard should be made [dealing with these issues and more] to officially confirm a luminary’s 100,000Hrs product lifespan – for various applications [but including long-term material tests]
We would expect a 100,000hr performance luminaire would need to have extensive component testing, to ensure all the components will last this long, we also believe the Ta rating would be vitally important [there may have Ta limits lower than other products]
As components such as gaskets/paint/capacitors/connectors/ solder connections /heatsink paste would have to all last for 100,000Hrs – we would expect the cost of the unit to be higher than usual.
Another concern is - would the product life span test, include simulating the actual conditions the luminaire will be exposed to on your particular site?
Q-If unforeseen failures do occur – will the supplier cover the labor costs as well as replacing the products.
One point to consider is the fact that every year LED are getting more efficient- after 50,000Hrs, the next generation of products could provide even greater energy savings.
Q- Which is preferred- a 100,000hr product running at 130 lumen per watt- or a 130 lumen per watt /50,000-Hr product eventually being replaced by a 200/250 lumen per watt product for the next 50,000Hrs [possibly with additional intelligent energy saving features]?
Also bear in mind – a new high-tech material has been discovered – called Graphene. When graphene technology is used to enhance LEDs /capacitors – we may see a great leap forward, in terms of higher Ta ratings/energy efficiency/LED lifespan/robustness.
Electrolytic capacitors, are often a weak link in terms of temperature handling – carbon based super capacitors are now arriving, with increased capacity/smaller size/ higher temperature ratings – the shape and design/handling abilities/efficiency of luminaires will change!
A graphene technology filament light emitter has also been patented –with a potential for very high lifespan and temperature handling- this could provide more options in addition to LEDs.
Imagine finding out after 50,000hrs that the new products work far more efficiently- making it worth your while to change the 100,000Hr lifespan unit’s half way through their service life – having paid extra for the 100,000hrs product and its extended warranty?
Future energy costs v future developments?
100,000Hrs constant running time equates to 11.4 years- by that time the cost of electricity may have risen dramatically – and, new units could provide greater energy savings – it is worth considering the possible economics.
Not so long ago, we saw a jump from 90 lumens per watt to 130 lumens per watt – this trend continues.
The maximum theoretical lumen per watt limit [by the laws of physics] is 683Lpw! It is not hard to imagine that 200 lumens per watt performance, will arrive on the market in 5 years’ time – or even greater, with the introduction of new graphene technologies [without considering the possibility of new types of technology being invented]
We do not predict a fall in electricity costs over 11 years– the current data suggest the opposite will occur.
Energy managers must consider the future effects of economic changes v potential technological improvements – when thinking ahead over such a long term period, bearing in mind - the last 11 years have seen a profound improvement in product efficiency- which will continue.
Thank you for reading this blog.