700.12

[hillbilly1]

I have a situation where the generator provided by the customer has a 10 second delay before it even tries to start. Generac 60 KW 277/480 wye with the Nexus controller. The factory claims the delay cannot be removed, and the customer is using an Eaton transfer switch which requires a two wire start. Generac has provided a two wire start module, but by the time the generator actually starts, and the transferswitch accepts the voltage, it is around 17 seconds. If started using the manual start switch it starts almost imediately. Has anybody had this problem before? And is there a cure other than getting a real generator? The reason we ended up with this one is because of the long lead time for any other generator, and the job completion date will not allow for it. (the Man/Off/Auto switch is soldered in to a pcb, so I can't intercept the "Man" wiring.)

 

[pete m.]

Just for clarification is the genset/transfer switch actually an article 700 application? Is there any way it could be viewed as a 702 installation?

Pete

 

[steve66]

Assuming it is an article 700 installation, NFPA 110 has a whole list of requirments for emergency generators. If the generator has a intentional 10 sec. delay, I highly doubt it would meet many of the other requirements.

But your post is a little confusing - usually it's the ATS that has a start delay time. The generator normally starts as fast as it can once it gets a signal from the ATS.

Or it is just taking the generator 10 sec. to get the voltage and frequency stable enough for the ATS to accept it?

 

[hillbilly1]

Assuming it is an article 700 installation, NFPA 110 has a whole list of requirments for emergency generators. If the generator has a intentional 10 sec. delay, I highly doubt it would meet many of the other requirements.

But your post is a little confusing - usually it's the ATS that has a start delay time. The generator normally starts as fast as it can once it gets a signal from the ATS.

Or it is just taking the generator 10 sec. to get the voltage and frequency stable enough for the ATS to accept it?

This is a Generac unit, there backwards to everybody else, the generator controls the transfer switch,( if you use their transfer switch) instead of the transfer switch controlling the generator. Generac finally came up with a $4000 dollar solution by replacing their controller with an industrial controller.

 

[ceb58]

This is a Generac unit, there backwards to everybody else, the generator controls the transfer switch,( if you use their transfer switch) instead of the transfer switch controlling the generator. Generac finally came up with a $4000 dollar solution by replacing their controller with an industrial controller.

It depends on which ATS is used. If the HTS switch is used then yes the gen. controls the ATS. The HTS is the "dumb" switch and the settings are done through Gen-Link software or through the control pad. If it is a GTS or RTS then the switch controls the generator. The only thing the controller dose,if it is a H-panel or nexus is monitor the gen. for common warnings and alarms. The ATS will control the line interrupt, transfer,exercise and shut down time.

 

[hillbilly1]

It depends on which ATS is used. If the HTS switch is used then yes the gen. controls the ATS. The HTS is the "dumb" switch and the settings are done through Gen-Link software or through the control pad. If it is a GTS or RTS then the switch controls the generator. The only thing the controller dose,if it is a H-panel or nexus is monitor the gen. for common warnings and alarms. The ATS will control the line interrupt, transfer,exercise and shut down time.

This one is a Nexus, the Generac Tech had to add the two wire start module to work with the Eaton transfer switch, Most of the smaller Generacs use the "dumb" transfer switches, at least the 100+ that I have installed. They may be doing something different now, just installed a 125 KW Onan last weekend, but the majority of installs I do are Kohler and Cat bigger units, 600 to 1 meg