Progressive EMS-HW50C unit

Learjet wrote:
For reference the Hartland Contactor in the EMS needs 88 votls to close and will drop out 20-77 volts, according to their website.

So yes, even in by-pass you will still get the contactor to open with extreme low voltages.

http://www.hartland-controls.com/#!blank/c1pqo

ktmrfs wrote:
just the info I was looking for, thanks. So that indicated what I expected, the little honda 2000, doesn't just drop below 104V, it must be dropping down below 70ish volts, which is consistent with sound guys data. However, It only drops down for a fraction of a second, as soon as the relay opens, it pops back up, and relay closes again, then repeat.

Yeah, exactly what happens with my own EU2000i, voltage momentarily drops to just 58 volts :E - short duration but enough cycles that even my $20 DVM can catch it, as shown in my video. Without the EMS in the circuit voltage does recover quickly but with it in place the contactor chatters like crazy.

Line power will very very seldom exhibit that type of behaviour, the line power is "stiffer", much lower source impedance so if it is dropping down below 70V you are REALLY drawing lots of power, Even a 75A load or so on a 15A branch circuit (what a 1hp motor draws for a few cycles on startup under load) will only drop the voltage down to around 100V, maybe 90 worst case.

I've never heard of line power being referred to as "stiffer" but yeah, that's about what it is. One of my videos I linked to earlier shows a nominal 120 vac 15 amp source dropping briefly to ~ 105 vac as the A/C compressor ramps up to speed, then recovers quickly following that - nowhere near the severe drop when source power is being supplied by my EU2000i genset. When I repeated this test back in the summer with my current Dometic A/C and the EMS in the circuit there was no contactor chattering at all when running on a 120 vac 15 amp line power source, only when the source was my EU2000i.

However, I suspect the EMS electronics is designed such that it doesn't catch the generator short cycle dropouts AND it can't do anything about the relay chatter with generators, that's a mechancal/electrical function of the relay itself.

Which I'm sure is why Progressive's official position is that their EMS is to be used only with conventional land line power.

On another related topic I went ahead and installed a switch in my Progressive EMS-HW30C so I can switch the delay from 15" (which I would use most of the time) to 136" (which I would use when running the A/C in the summer) without having to open the box and remove the delay jumper. Works like a charm. :B

Progressive Industries EMS-HW30C Delay Switch Mod (4 pics)