Single-Phase VS Three-Phase Generators Explained
If you aren’t familiar with the different variations and applications of generators, then it’s likely that you will find the power generation industry’s jargon confusing.
We often have enquiries for generators, where customer’s require guidance on whether to select a single-phase or three-phase generator. We work with our customer to understand their application, to allow us to specify the correct machine. So that you know the difference between the two types of generator, the team at Generators OnLine have created a quick but informative guide covering the key differences between the two machine types.
A brief overview of single-phase generators
A single phase (1Ph) generator requires one of each of the following cables (Live, Neutral & Earth.) and typically operates at 230 volts in the UK.
A brief overview of three-phase generators
As the name might give away, three-phase (3Ph) generators utilize three live cables, along with an earth, and a neutral. These machines often operate at 415volts.
- Number of conductors
We have already mentioned this above, but it’s an important point. A single-phase generator uses only one conductor (L1), whereas the three-phase generators use three (L1, L2, L3). Our advice to customers is to match the generator equipment to the customer application and so establishing what they’re trying to achieve is always step one.
Occasionally, customers request that we nullify L2 & L3 on their previously purchased three phase generators, to enable use in single phase applications. This, we at Generators OnLine can (and do!) do, utilizing our in-house team of electricians.
- Electrical generation capability
The number of conductors in use has a positively correlating effect on the overall electrical production capability of a generator. For this very reason, three phase generators have a higher output rating as (regardless of engine and alternator) they can provide triple the output.
For this reason, above a break-point of c. 25kW, we typically advise a three-phase machine is supplied and that our engineers are employed to recommend a solution to power the customer’s single-phase appliances. This allows us not to compromise on the capability of the three-phase machine, when presented with a challenge of single-phase load.
- Application usage
Single phase generators are best suited for jobs with lower power output demands and so are often dispatched for domestic housing, small events, mobile food trucks, construction sites etc. Three phase generators are more suited for larger applications and so commonly we see these generators heading to commercial premises, industrial sites, marine environments amongst a whole host of other sites.
- Reliability & Durability
Power continuity is arguably the most important element of any power solution. This rule applies whether a generator is running in a prime or standby application. With this in mind, a single-phase generator has a distinct and inherent disadvantage, in that in operates using only one conductor. Therefore, if that one cable or ‘phase’ was to fail, the whole power solution fails.
Fortunately, with three-phase generators, in some fault conditions if a fault is to occur with one of the phases, (e.g. L1) then the other two (L2, L3) could remain operational ensuring a continuous power supply.
In mission critical applications, Generators OnLine mitigates this risk by recommending the combination of two generators (1 running, 1 standby) achieving an N+1 redundancy set-up.
How we can help you
At Generators OnLine, as one of the UK’s most reputable suppliers of home and commercial backup generators, we have a wide range of both single and three-phase generators available, from stock. Our team of experts is on hand to work with customers on their application, whether three phase or single phase and look forward to getting involved with more power generation projects soon!