"Will it run on my Honda 2200" is the most asked question on every RV forum and the one no retailer answers on the product page. Here are the numbers.
Coleman-Mach power draw
Figures from Coleman-Mach product literature and the 2025 Coleman-Mach catalog at 115 V. Your unit's rating plate is the final word. Where Coleman publishes no number, the table says so instead of guessing.
| Series | BTU | Running amps, cooling | Running watts (95F outdoor) | Locked rotor (start) amps |
|---|---|---|---|---|
| Mach 3 Plus | 13,500 | 12.8 (15.4 in desert conditions) | 1,650 (1,900 desert) | 63 |
| Mach 15 Plus and Mach 15 Quiet | 15,000 | Same chassis and electricals as the Mach 3 Plus: 15.3 full load | 1,650 (1,900 desert) | 63 |
| Mach 18 (Everest VS-18 inverter) | 18,000 | 12.7 turbo, down to 5.0 eco | About 916 nominal | Low: the inverter compressor ramps up |
| Mach 8 Plus 13.5K | 13,500 | 12.5 (15.3 in desert conditions) | Not published | Not published |
| Mach 8 Plus 15K | 15,000 | 14.2 (18 in desert conditions) | Not published | Not published |
| Mach 15 Heat Pump | 15,000 | 14.8 (15.4 heating) | Not published | Not published |
| Mach 10 Heat Pump | 15,000 | 14.4 (16.0 heating) | Not published | Not published |
| Heat strip 38203-4551 | 5,600 heat | 16.0 | 1,800 | n/a |
Running watts are the easy part. The problem is the compressor start: for a fraction of a second a standard 13,500 or 15,000 BTU unit pulls 60-plus amps, over 7,000 W. That inrush is what trips a small generator. The Mach 18 avoids it because its inverter compressor ramps up instead of slamming on.
Generator sizing
The Mach 3 Plus and Mach 15 share the same start current, so we size them the same: plan on 3,500 W to start either one without a soft start.
| Generator | Mach 3 / 15 (13.5K / 15K), stock | Same unit with soft start | Mach 18 inverter |
|---|---|---|---|
| 2,000 W inverter (Honda EU2000i) | No | Usually, at low altitude, nothing else running | Not rated by Coleman at 2,000 W |
| 2,200 W inverter (Honda EU2200i, Yamaha 2200) | No, trips on start | Yes, in eco mode off | Yes, no soft start needed |
| 3,000 W inverter | Marginal; it may trip on start when hot or at altitude | Yes, with headroom for a converter | Yes |
| 3,500 W and up, or two 2,200 W paralleled (4,400 W) | Yes, one unit | Yes | Yes |
| Onboard 4,000 W (Onan 4000) | Yes, one unit; two units only with soft start on both | Two units | Yes |
| Onboard 5,500 W and up | Two units | Two units plus loads | Yes |
Coleman publishes no start current for the Mach 8 Plus or the heat pumps, so we make no generator claim for them. The 1497-3601 soft start fits every profile, Mach 8 and heat pumps included.
Altitude, heat and a tired generator all take capacity away. A 2,200 W generator at 7,000 ft in Colorado is a 1,700 W generator.
What a soft start does
A soft start kit (Coleman 1497-3601, or a Micro-Air EasyStart) ramps the compressor up over a second or so instead of slamming it on, cutting the start surge by roughly 60 to 70 percent. It mounts inside the unit's shroud, wires into the compressor circuit, and takes about 30 minutes. It does not change running draw.
Buy a soft start if you run a 2,000 to 2,200 W inverter generator, if you want to run two ACs on an Onan 4000, or if you are on a 30 A pedestal and the AC start browns out the lights. Skip it if you are on 50 A shore power with one unit, or if you are buying the Mach 18.
Related
Soft start kits. Coleman-Mach 18 inverter units and kits. Every Kate RV unit and kit page lists running amps and, where Coleman publishes the numbers to support it, the minimum generator in the At a Glance block.