generator delay

[Titus]

I recall seeing this topic discussed previously, but I don't remember if there was a solution.

After starting the generator there is a delay of about 30 seconds at which time the microwave gets power momentarily. (The microwave clock lights up and it beeps.) Other generator circuits may briefly get power too - I'm not sure. Then the microwave goes dead for a minute or so. After this additional minute the Precision Circuits panel lights up and it provides power to the microwave - and everything else. So takes 1 1/2 minutes in total before you we can use the microwave. I can see the need to let the generator stabilize and get full oil pressure before producing power. But I think that 30 seconds is enough for that. (Remember that emergency standby generators provide full power in just a few seconds.) Do you know if the total time of 1 1/2 minutes is adjustable? If so, is the adjustment within the generator controls or the Precision Circuit controls?

[Mollysdad]

Is that an onboard generator or an aftermarket one like a Honda?
If it's built in, it might take a few seconds for the automatic transfer switch to engage. Frankly, I've never seen 1 1/2 minutes of running before power is unleashed.

[Titus]

It is an on-board generator - Cummins-Onan HGJBB.

I had not thought about the transfer switch being the culprit for the delay. I went to the info. on it (Parallax Power Supply ATS 301) and you have identified part of the issue. There is a generator delay (one place says 20-30 s, another place says 20-25 s) for the generator to stabilize. This appears to be the 30 s. before the brief microwave power beep that I described. This time delay can be disabled by moving jumper J1. I suppose if I move J1 I will have only the second delay of ~ 1 minute. They do not mention a delay for the shore power, and there is only a 10-15 s delay when I plug into shore power.

I am not sure what causes this second delay - but whatever it is may be enough time for the generator to stabilize. Maybe a call to JC to see if anybody there knows, or will tell me...

BTW, I have a Progressive Industries EMS-30HC power protector, but it is between the shore power connector and the transfer switch and thus should not be causing the generator delay. If I had it on the output of the transfer switch (protecting both generator and shore power) I could see how it might account for a delay.

[Air99]

Originally Posted by Titus

I recall seeing this topic discussed previously, but I don't remember if there was a solution.



After starting the generator there is a delay of about 30 seconds at which time the microwave gets power momentarily. (The microwave clock lights up and it beeps.) Other generator circuits may briefly get power too - I'm not sure. Then the microwave goes dead for a minute or so. After this additional minute the Precision Circuits panel lights up and it provides power to the microwave - and everything else. So takes 1 1/2 minutes in total before you we can use the microwave. I can see the need to let the generator stabilize and get full oil pressure before producing power. But I think that 30 seconds is enough for that. (Remember that emergency standby generators provide full power in just a few seconds.) Do you know if the total time of 1 1/2 minutes is adjustable? If so, is the adjustment within the generator controls or the Precision Circuit controls?

Mine behaves exactly the same way, and consider how complex the circuitry and the need for things to stabilize, I think it’s worth the wait.

[Titus]

You may be right, but I have never been know for my patience. I am content to wait if there is a good reason to do so - just am not sure that there is.

[Rig Rat]

Our Onan genny operates with the 2 described delays as well. However, after the second delay and before any appliances are activated, the readout shows 7 amps being pulled from the generator.

If we try using the microwave after the 2nd delay, it will shut itself off after a few seconds and the generator then cycles through another delay, etc.,etc.

We have found the only way we can get the microwave to work while being on generator power is to set the microwave to 60% power and then it will work.

The readout at that time is usually 19-20 amps.

Has anyone else had this problem or have an idea why we are pulling 7 amps w/o anything turned on?

[Titus]

The charger is fed by the generator, so low batteries will draw generator power even if 'nothing is on'. Trying turning the charger/invertor to 'off' and see if the 7 drops to 0. Unless you have the newer 'high tech' inverter microwave the use of 60% power will only cycle it between full power 60% of the time and 0 power 40% of the time. So you would still see 19-20A for 60% of the time. We have never used anything other than full power on our microwave. I don't remember what the microwave draws, but I was thinking it was less than 19-20A.

I think the cycling that you describe is the EMS unloading the generator circuit to get < 20 A. Two things you could do:
1) Turn off the Charger when you want to use the microwave.
2) Set the charging current to a lesser percentage of max battery capacity. This is adjustable on my upgraded Magnum remote, and it may be on the standard Magnum remote too.

[Lily&Me]

I believe you are supposed to start the generator with no load at all, let it run a few minutes, then add loads gradually.

Maggie

[Titus]

Yes, Maggie, you are correct. The delays allow the generator to start without any load. Even if you had everything turned on (electric water heater, AC, microwave, etc.) they would not get power until after the delay. The purpose of my inquiry was to understand what is causing the various delays, and to see if one of them can be eliminated. I suspect that there is more than one thing trying to delay load to the generator, and that having only one of them is sufficient. Emergency stand-by generators are required to produce full power in a matter of seconds. So I don't need 120 seconds of delay.

[Boxster1971]

Originally Posted by Titus

The charger is fed by the generator, so low batteries will draw generator power even if 'nothing is on'. Trying turning the charger/invertor to 'off' and see if the 7 drops to 0. Unless you have the newer 'high tech' inverter microwave the use of 60% power will only cycle it between full power 60% of the time and 0 power 40% of the time. So you would still see 19-20A for 60% of the time. We have never used anything other than full power on our microwave. I don't remember what the microwave draws, but I was thinking it was less than 19-20A.

I think the cycling that you describe is the EMS unloading the generator circuit to get < 20 A. Two things you could do:
1) Turn off the Charger when you want to use the microwave.
2) Set the charging current to a lesser percentage of max battery capacity. This is adjustable on my upgraded Magnum remote, and it may be on the standard Magnum remote too.

I don't think you can stop the Magnum charger from charging if there is 120VAC power applied. You would have to trip the Charger/Inverter breaker to stop that load.

Also on my 2013 model I've found that the EMS will dump the load and restart the generator 2 minute power up sequence if the load goes to 18A. This is a minimum setting according to the EMS tech data for GEN mode. This is very frustrating when trying to run the A/C off generator as the startup load briefly exceeds 20A. I have been using a work around by tripping the Microwave breaker that also provides power to the EMS. Without the EMS the generator can run the A/C just fine. If running A/C on generator was more important to me I'd probably try one of the easy start capacitors to lower the A/C start load.

[Titus]

I was thinking there was an 'off' switch for the charger, but you may be right.

I tested the AC to see if you could be run from the generator and found that it could. Lucky I guess. But other than that test I have only used the generator to recharge batteries (before I upgraded solar) and, most often, to run the microwave. I cannot see upgrading to a 2000W magnum just to run the microwave off batteries. But could see installing an inverter microwave.

[Alex AVI]

Originally Posted by Boxster1971

I don't think you can stop the Magnum charger from charging if there is 120VAC power applied. You would have to trip the Charger/Inverter breaker to stop that load.

I think you can by going to CHARGER MENU and changing it to STBY Mode. It would still present 120VAC to inverter outputs but charger circuits are de-activated. Note: you can not change to STBY until 120VAC is in. If display shows "No AC In" , then wait until it senses 120VAC.

I read on the generic Cummins gen manual that our chargers run in the range of 6A to +20A draws depending on charging state, BULK being the biggest draw. So, if charger can pull that much current, not surprising the gen behaviour. FWIW, Cummins also specify 2 mins. wait time before loading. But very, very vague on explaining why, just the typical "for optimum performance and longer life" stuff. And no mention of built-in delays. I did not time mine when I was going through A/C testing during my Firefly upgrade. But based on how long I waited, it had to be min. 2 mins. also before A/C kicked in after gen 1st starts.

[rmkrum]

Some generators need time for the windings to warm up a bit and dry out before putting a load on them. Many larger emergency gensets have heaters to keep the stator windings and interior of the alternator assembly dry when on standby. It helps prevent electrical flashover and arcing in the windings when you put a load on them. Dry insulation lives longer, and that’s probably why they suggest some period of unloaded run time for RV generator sets.

[Boxster1971]

Originally Posted by Alex AVI

I think you can by going to CHARGER MENU and changing it to STBY Mode. It would still present 120VAC to inverter outputs but charger circuits are de-activated. Note: you can not change to STBY until 120VAC is in. If display shows "No AC In" , then wait until it senses 120VAC.

I read on the generic Cummins gen manual that our chargers run in the range of 6A to +20A draws depending on charging state, BULK being the biggest draw. So, if charger can pull that much current, not surprising the gen behaviour. FWIW, Cummins also specify 2 mins. wait time before loading. But very, very vague on explaining why, just the typical "for optimum performance and longer life" stuff. And no mention of built-in delays. I did not time mine when I was going through A/C testing during my Firefly upgrade. But based on how long I waited, it had to be min. 2 mins. also before A/C kicked in after gen 1st starts.

Right on - forgot about using the Magnum menu. Here is procedure from manual. But it is a bit more steps than just tripping the breaker.

[Alex AVI]

Originally Posted by Boxster1971

But it is a bit more steps than just tripping the breaker.

Haha, yeah, either way it's a PITA Can this be "kill-switched" too like Fusion?