Firman Generator Details

Generators 101

What is an inverter?
FIRMAN inverter generators electronically control the engine RPM up and down to the required demand of your appliance instead of running at a high RPM full time. The results are improved fuel efficiency.

Inverter generators also produce lower emissions and run at a very quiet 58dB thanks to the insulated housing and FIRMAN whisper series muffler.

FIRMAN inverter microprocessors are engineered to create high quality power that is clean enough to power all of your sensitive electronics and equipment. FIRMAN inverters are also all parallel compatible. You can double your power by connecting 2 FIRMAN inverters together with our parallel kits.

An inverter generator takes the AC current and converts it into DC current, and then inverts it back to clean AC power.

Who makes FIRMAN’s engines?
FIRMAN does, we manufacture our generators from the ground up. We make everything on the generator from the frame to the engine.

Accessing Serial Numbers

Where is the serial number located on the Hybrid Series?
At the bottom side of the gas tank underneath where the handle is mounted. On the specification sticker, on the gas tank, it should say “Serial #”. The serial number should be 10 digits long and only numbers.

Where is the serial number located on the Whisper Series?
On the Whisper Series, the serial number is on top of the generator.
The serial number should be 10 digits long and only numbers.

Where is the serial number located on the Performance Series?
On the Performance Series, the serial number is on the top half of the gas tank on the handle side.
The serial number should be 10 digits long and only numbers.

General Use and Maintenance

What type of oil should I use in my FIRMAN generator?
Conventional 10w-30 motor oil.
If you are operating in below freezing temperatures, use full synthetic 5w-30.

What type of gas should I use?
Regular unleaded 87 octane from a gas station

Higher octane fuels and rec fuel will require swapping to the proper NGK plug (spark plug)  to prevent carbon build up from fuel fouling

How long will the generator run on a 20lb propane tank?
LPG burns at about 1 gal per hour at 50% load. So a 5 gallons (20L) Propane tank will last you 5-6 hours at 50% load for our bigger Hybrids Units.
For the Inverters, a 5 gals Propane Tank can last you up to 8 hours at 50% load.

Why does my generator run, but no voltage to front panel?
On Hybrids (Dual/ Tri fuel), switch the two circuit breakers on the front control panel to the ON position
If nothing or low voltage shows up on the multi display meter, the AVR could need to be replaced or the ECM could need to be reset. Please contact Firman Tech Support.

What Spark Plug do I need ?
Please refer to the owner's manual for spark plug references. A few different alternative spark plugs will be listed.

As a reminder, you can download each product's manual from the website.

Is there a break-in period?
Changing the oil after the first 25 hours of use is the only break in procedure we recommend

Can I convert my generator to run on natural gas or propane?
No, we do not sell or recommend conversion kits as it would count as a modification and void the warranty.

Our generator was engineered and tested to an OEM specific fuel, if this fuel is change it will cause engine damage.

Can I parallel any two of your inverter generators together for more power?
Yes, you can parallel them together for more power.
For W01781/W01782 and all our 3000W Inverters: You will need the Parallel Kit 1201.
For W01682/W01784: you can parallel them together only with the cables they come with.

Can I add a remote starter to my generator?
No adding a remote start to a unit would count as a modification and void the warranty.
On HYBRID models, the propane valve would have to be left open, which means the fuel will continuously flow into the cylinder which is a fire hazard.

What is the Total Harmonic Distortion or THD ?
The THD is the fluctuation of electricity and determines the potential for problems with high-end electronics or those considered sensitive when the power goes out.

Our generators are safe with sensitive electronics.
For PERFORMANCE and HYBRID, it is roughly 11-14%.
For WHISPER, it is less than 3 %.

Do you have exhaust extension kits? Can I extend the exhaust by myself?
We do not offer any exhaust extensions. And we certainly do not recommend you trying to extend the exhaust by yourself. Doing so can cause your exhaust to back feed and prevent your generator from running well causing engine damage. It will also void the warranty.

Is it possible to reduce the noise on my generator?
No, it is not possible to reduce the noise of your generator as we do not offer any compatible noise reduction kits.

Can I install an extended run fuel tank or fuel cap?
No, this is very dangerous as it makes your generator prone to leaks and fire. It will also void the warranty on your generator.

Can I set up the generator with an automatic transfer switch?
No, our generators are not compatible with an automatic transfer switch.

They are compatible with a regular transfer switch, you will have to start the generator yourself in case of power outage. Please contact technicians for installation.

How do I store my generator?
This is crucial for your FIRMAN well being to respect storage conditions. If you want your FIMAN to be ready when you need it, please refer to the Blog Article "How to store my FIRMAN Generator".

Where can I purchase parts?
You can purchase FIRMAN parts by calling us at 1-844-FIRMAN1 (1-844-347-6261). You can also chat with our support staff, who’d love to help you out.

Can I use my generator 24/7?
We recommend running it for no longer than 14 hours with a 2-3 hour break in between.

What do I need to know for my Natural Gas Installation?
Needs to be done by a plumber or professional + need to purchase the 10ft or 25ft Natural Gas Hose Kit on FIRMAN Website. It needs to be a ½ inch hose with a 3/8 female flare.

Max of 101 000 BTU’s // Psi between 0.25 and 0.40

How can I protect my FIRMAN generator from the rain?
You need to protect the gas tank & the plugs from the rain but leaving both extremities open to the air so the air can go in and out the generator.

You can search for Generator Housing online, or install a big piece of flatwood on top.

Do I need a High-Altitude Jet for FIRMAN generator?
If the elevation exceeds 3000 ft, yes.

Increase in altitude means a decrease in oxygen. Lower
oxygen levels mean the fuel mixture will be too rich. If the fuel mixture is too rich this leads to carbon fouling of the plug and spark arrestor, if left
unchecked this will cause too much backpressure on the engine, and it will not
run properly. You will need to order a High-Altitude Jet trough Tech Support (phone line or Chat). It is covered by the warranty.