Please help me determine the correct wiring and functionality of the QUATTRO 5KW/48V/120V system. Please review the following information. I am providing a simplified drawing of the proposed wiring. Please identify any corrections or suggestions you might have.
I am also describing the circuit functionality of three different power source conditions. Please confirm that I have correctly identified the circuit paths in each of the conditions.
Condition 1. When connected to 240 volt Shore Power:
The transfer switch terminal HOT1 will connect Shore Power L1 to the Quanttro IN1 and terminal HOT2 will connect Shore Power L2 to Quanttro IN2.
The Quanttro will connect Shore Power L1 through OUT1 to Load Center MAIN (1).
The Quanttro will connect Shore Power L2 through OUT2 to Load Center MAIN (2).
Voltage across OUT1 to OUT2 is 240 volts.
Voltage across OUT1 to Neutral is 120 volts and OUT1 to Neutral is 120 volts.
Condition 2. When 120v generator is running (Generator L1 bridged to Generator L2)
The transfer switch which will connect Generator (L1 L2) to the Quanttro IN1 and Generator (L1 L2) to Quanttro IN2.
The Quanttro will connect Generator (L1 L2) through OUT1 to Load Center MAIN (1).
The Quanttro will connect Generator (L1 L2) through OUT2 to Load Center MAIN (2).
Voltage across OUT1 and OUT2 is 0 volts.
Voltage across OUT1 to Neutral is 120 volts and OUT1 to Neutral is 120 volts.
Condition 3. When no Generator or Shore Power is available
No power to Quanttro IN1 and Quanttro IN2.
The Quanttro Inverter will power 120v through OUT1 to Load Center MAIN (1).
The Quanttro Inverter will power 120v through OUT2 to Load Center MAIN (2).
Voltage across OUT1 to OUT2 is 0 volts.
Voltage across OUT1 to Neutral is 120 volts and OUT2 to Neutral is 120 volts.
The Quattro selects AC-in-1 OR AC-in-2, whichever has power.
Putting shore L1 on AC-in-1 and shore L2 on AC-in-2 doesn’t make sense.
Only one of those will make it through to the output(s).
On the output, the AC-out-2 output relay normally disconnects when grid power is not present, though that behavior can be changed.
Thank you for your response and particular for the block diagram. I have some visual limitations and require a computer to see and read so the paper documentation is of little use to me. Where can I find the block diagram?
I clearly misunderstood the IN1 and IN2 functionality. My goal is to use both leg of the shore power when connected.
Rick, Once again thank you so much for your reply and the links. I have already purchased the Quattro 5K and feel that the 3K unit would not be sufficient.
I’m uploading a schematic sketch with an external relay on L1. I would greatly appreciate your opinion.
In principle, that diagram should work for what you want.
Specific Comments
(1) Depending how much current you are using, a full contactor may be needed rather than just a relay, though they do make a loud ka-chunk when they are activated. I’ve used HVAC-style contactors for this kind of application in the past. You’ll need a 120 VAC coil variety.
(2) The control of the relay or contactor is important, you show the L1 shore power itself activating it.
It is possible for the Quattro and this relay to be out of sync, so that L1 is shore power, and L2 is inverter power. This can happen, for example, if the Quattro rejects the input power due to frequency or low-voltage, but the relay is still active. Worse, the shore power neutral will be disconnected at the input relay in the Quattro, so the L1 won’t really have a path back to Neutral. Depending on how you do ground bonding, you could get objectionable current on the ground wire, which is a no no.
(3) You could instead control the relay using AC-out-2 L power from the Quattro, because we know when the Quattro disconnects from the grid for any reason, it will not be powered. That should avoid the edge case described in (2).
(4) Any 240V loads you have in the panel will see 0V when inverting, but I assume you know that.
Quick Reaction
You’ve covered the steady state behavior you want, but the devil is in the switching sequence.
There is a lot of complexity with those relays/contactors that increases the risk.
You are going to be unhappy with that relay using the generator line to decide to switch between generator and shore, or generator and inverter. It may even be dangerous depending on the sequence of events, I’ll have to give that some more thought.
The Quattro should be the device making the decision on whether to use the generator or not. It waits for stable voltage before switching from shore to generator, or inverter to generator.
For me, your problem boils down to this statement (correct me if I am wrong)
L1 and L2 should be bonded together at the panel only when running on inverter OR when running on 120V generator, otherwise, L1 should come from shore power.
So a single SPDT relay could be the only device needed, provided that its coil is driven by AC-Out2. The Common would be connected to L1 in the panel. The NClosed would be connected to L2 in the panel. The NOpen would be connected to L1 shore power.
I need to see if the AC-out2 relay in the Quattro can be programatically controlled to also disconnect when the generator is in use. The Programmable Relay assistant may help here. If that is possible, there will be a single point of control for where L1 panel power comes from.
The relay will only turn on when AC-In 2 (shore power) is present for 1 second.
So L1 will come from shore power.
At all other times, the relay is unactivated, so L1 is connected to L2 in the panel.
You can actually use 0 seconds so it happens immediately.
Does this do what you want?
I’ve had good luck with this relay (have 2). It is rated 80A per pole (though you only need one pole). I actually parallel the poles for 160A because I don’t trust the ratings on these low-cost relays. Select the 110 VAC coil option, not the 12V. There are other options out there for sure.
