generator block heater and battery charger

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anbm

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Emergency generator: does generator's block heater and battery charger need to be powered off a emergency panel
(emergency panel is fed out of ats via generator power and normal power source). Thank you.
 
The block heater is not necessary once the generator is started. Same for a battery maintainer as long as the generator includes an alternator or magneto for when it is running.

Tapatalk!
 
A lot of these type of questions can only be answered by NFPA 110. If you are doing any Art. 700 or 701 systems, best to consult this or you can have some real rude surprises at inspection- and not just from the electrical inspector.
I've seen some real costly situations where the EC does not realize that there is more than the NEC involved.
 
Emergency Gen Peripheral Loads

Emergency Gen Peripheral Loads

I'm not a code guy but what I typically see in the field is that anything that supports the operation of the genset is fed off of the load side of one of the ATS's fed from the genset so as to be temporarily interrupted but powered back up once the main load is transferred and running on emergency power. Not sure what the NFPA110 has to say about this. Anyone to comment?
 
texie said:
A lot of these type of questions can only be answered by NFPA 110. If you are doing any Art. 700 or 701 systems, best to consult this or you can have some real rude surprises at inspection- and not just from the electrical inspector.
I've seen some real costly situations where the EC does not realize that there is more than the NEC involved.
Click to expand...

Curious, would you care to be more specific?
 
anbm said:
Emergency generator: does generator's block heater and battery charger need to be powered off a emergency panel
(emergency panel is fed out of ats via generator power and normal power source). Thank you.
Click to expand...

No on the block heater. Yes on the charger
700.12 (B)(4)


Battery Power and Dampers.
Where a storage battery
is used for control or signal power or as the means of
starting the prime mover, it shall be suitable for the purpose
and shall be equipped with an automatic charging means
independent of the generator set. Where the battery charger
is required for the operation of the generator set, it shall be
connected to the emergency system. Where power is required
for the operation of dampers used to ventilate the
generator set, the dampers shall be connected to the emergency
system.
Click to expand...
 
ceb58 said:
No on the block heater. Yes on the charger
700.12 (B)(4)
Click to expand...

IMHO, that only applies where the charger is required while the engine is running, i.e. when there is no provision to charge the battery directly from an auxiliary winding on the generator or an alternator on the prime mover.

Having a battery maintenance charger connected to the emergency system should not make any difference in the availability of the battery for starting the generator. When the generator is not running and POCO power is not available, the charger connected to the the emergency system will not work any better than one connected to the normal power system.
But with Code language which is not crystal clear and the need to satisfy an inspector, better safe than sorry.
 
As been said many smaller generators such as Generac's home back up units 20kw and less do not have a charging system on the engine, their Quite source and larger ones do have a 30 amp alternator to maintain the battery, if the generator doesn't have a charging system while the engine is running then the battery maintainer must be connected to the load side of the transfer switch or the panel it supplies so that the battery will be kept charged while the generator is running, otherwise it wouldn't be long before it is depleted and the generator shuts down, but as far as the block heater goes, the engine will produce more then enough heat to keep it warm while it is running so there is no reason to put this load on the generator, it should be supplied only from the utility, this should be the same for all generators emergency or just back up, most all commercial or industrial type generators will have an alternator to maintain the battery while the generator is running, if this is the case then the battery maintainer can be just put on the utility side of the transfer switch.

Also never use a trickle charger to maintain a maintenance free battery, Generac use to supply one and they would boil the water out of the battery and if you used a maintenance free battery that wasn't designed to have water added to it it would run dry and we have had several explode, after sever calls and e-mails to their engineers we finally got them to supply float chargers with the generators, and now they have the float charger built in their control system (Nexus system)
 
ATSman said:
Curious, would you care to be more specific?
Click to expand...

Sure. If you are installing a system to comply with Art 700 or 701 there additional requirements in NFPA 110. And if it used in a health care facility NFPA 99 will also come into play.

Not all machines are created equal and thus not all will qualify to be used in such systems. For example, a typical residential grade machine will not meet the requirements of 110 for various reasons. These types of gensets are typically used under the rules of Art 702, Optional Standby Systems where the rules are much less onerous. This is one reason that the term "emergency generator" should never be used when discussing a system that is really an optional standby system as they are different animals and have vastly different requirements for the equipment and installation methods.
 
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