Generator Installation for West Covina

Sizing a set to the coach rather than to the catalog

Sizing starts with a load list, not with a wattage number an owner heard. The heavy items are the roof air conditioners, and their starting surge matters more than their running draw. A compressor pulls several times its running current for a moment at startup, and a set that carries two air conditioners comfortably while running can stall if both compressors try to start at the same instant.

After air conditioning, the list continues: microwave, water heater on electric, residential refrigerator if fitted, washer and dryer, converter or inverter charger output, and whatever an owner actually plugs in. We add running loads, identify the worst realistic simultaneous case, and add surge headroom for the largest motor rather than for all of them at once.

Soft start devices on air conditioners change the arithmetic meaningfully. They reduce compressor inrush substantially, which can let a smaller set carry two units where it otherwise could not. On coaches where the generator bay physically limits set size, fitting soft start hardware is often the difference between the coach working and the coach not working.

Undersizing produces a set that runs constantly at its ceiling, which is hard on it. Oversizing produces a set that spends its life lightly loaded, which is the fouling problem that ruins generators. There is a correct band, and finding it is the point of the load calculation.

• Air conditioner starting surge, not running draw, sets the minimum size
• Soft start devices reduce inrush enough to change set selection
• Undersizing means running at the ceiling continuously
• Oversizing means a lifetime of light loading and carbon
• Propane sets deliver less output than gasoline for the same displacement

Mounting, structure and vibration isolation

A generator is heavy, it vibrates continuously, and it sits in a compartment that was not always designed to carry it. On coaches with a factory prep bay the structure is already there, with a slide tray, mounting points and an existing airflow path. On coaches without one, mounting becomes a fabrication project: a structural tray tied into the frame rather than into floor sheeting, sized for the weight plus the dynamic loading of road motion.

Isolation mounts are what keep engine vibration out of the coach, and they are consumable. Rubber hardens with heat and age, and once isolators are stiff the vibration transfers into the structure and into the exhaust system. When we replace a set, isolators are replaced with it rather than reused, because reusing them puts an aged component under a new machine.

Weight distribution matters on towables in particular. Adding a set well behind the axles changes tongue weight and handling, and adding it forward changes it the other way. On a fifth wheel or travel trailer that is already close to its limits, the position of a generator is a real engineering consideration rather than a matter of where there is space.

Access is the last mounting consideration and it is chronically ignored. A set installed where the oil filter cannot be reached will not get serviced. We plan the installation around the service points: oil drain, filter, air filter, spark plugs, strainer and the slide path if the unit is on rails.

Exhaust routing, airflow and carbon monoxide safety

Exhaust is the part of a generator installation with the highest consequence for getting wrong. Gas has to exit clear of the vehicle and away from every opening: windows, doors, roof vents, service hatches, the refrigerator vent, slide seals and, on commercial builds, service windows and customer areas. Prevailing airflow around a parked vehicle can pull exhaust back along the body, so tailpipe position and direction are chosen deliberately.

The exhaust system also has to accommodate movement. The set is isolated so it moves relative to the body, and a rigid connection between a moving engine and a fixed body cracks. Flexible sections, correctly located hangers and enough support to keep the tailpipe from drooping are all part of the install rather than accessories.

Combustion and cooling airflow are separate requirements. The engine needs air to burn and the enclosure needs air to carry heat away, and the compartment has to supply both without recirculating hot exhaust air back into the intake. Installing a set in a sealed bay with a single small vent is how a new generator ends up shutting down on overheat within a month.

Carbon monoxide detection inside the coach is checked as part of any generator installation. Detectors have a service life measured in years and expire regardless of whether they have ever alarmed. A generator installation on a coach with an expired detector is not a finished job, and we replace them as part of the work.

Fuel supply, propane and the connection to the coach

Gasoline and diesel sets draw from the vehicle tank through a dedicated pickup that terminates above the tank bottom, so the generator runs out before the vehicle does. Adding that pickup to a tank that never had one is a real job involving tank access, and on some chassis the practical answer is a different fuel arrangement entirely.

Propane sets are common on towables and on some van builds. Two constraints matter. First, propane sets produce less output than an equivalent gasoline unit because of the fuel's energy density, so sizing has to account for it. Second, vapor withdrawal from a propane tank depends on tank temperature and liquid level, and a generator plus a furnace plus a water heater on a cold morning can outrun what a small tank can vaporize. The symptom is a set that runs and then starves, and the cause is the tank rather than the generator.

Regulator capacity and line sizing follow from that. A regulator sized for cooking appliances will not feed a generator, and undersized supply line produces pressure drop under load that looks exactly like a fuel restriction in the set. We size the whole path rather than just connecting to the nearest tee.

All propane work is done by certified technicians, and every connection gets leak tested before the vehicle leaves. That is not optional and it is not something to shortcut on an installation that will be run unattended.

Transfer switch, panel integration and commissioning

A generator that is not correctly integrated with the coach's electrical system is a hazard. The transfer switch has to be rated for the coach service, not for the generator, since it carries the full load from either source. We do find 30 amp switches installed on 50 amp coaches after previous work, and that is a component running past its rating every day.

The switch also has to genuinely transfer rather than allow both sources to connect. Back feeding shore power from a generator is dangerous to anyone working on the supply side, and an interlock or a proper automatic transfer switch is what prevents it. On installations where a previous owner wired a generator into the panel without transfer equipment, correcting that is the first thing we do.

Bonding is the detail that gets missed. Neutral and ground bond exactly once in a correctly wired system. A generator with an internal bond feeding a coach that is already bonded upstream creates a second bond, which puts return current on the chassis and trips every modern ground fault protected pedestal. We verify the bonding arrangement as part of commissioning.

Commissioning closes the job. The set runs under a controlled load with voltage, frequency and current measured, transfer is tested in both directions, exhaust is checked for leaks with the engine hot, carbon monoxide detection is verified, and the remote panel is confirmed to report correctly. We do this in shop at Yorba Linda, about 22 miles from West Covina, because it needs load equipment and exhaust extraction. We do not offer mobile service. Call (949) 799-3387 to discuss an installation.