277/480 Volt service

[pfactor2]

I have to provide a underground service from FPL to stand alone service for a 277/480 volt, 5HP irrigation motor. The only other load is a irrigation timer. To my knowledge there isnt a small 277/480 outdoor panel available ( like six ckt. so I don't need a main). I'd like to just use a fusible disconnect ( after the meter and before the starter of course ) but what about the timer. Since the fuses will be 15 amp is it legal to tap a phase for the timer? Or any suggestion for the dilemma.

 

[mbrooke]

I have to provide a underground service from FPL to stand alone service for a 277/480 volt, 5HP irrigation motor. The only other load is a irrigation timer. To my knowledge there isnt a small 277/480 outdoor panel available ( like six ckt. so I don't need a main). I'd like to just use a fusible disconnect ( after the meter and before the starter of course ) but what about the timer. Since the fuses will be 15 amp is it legal to tap a phase for the timer? Or any suggestion for the dilemma.

I would make a wild guess that tap rules could apply to two disconnects. I see it frequently done on strip mall services 6 throws and under. I would ask the supply houses to on the smallest 480volt outdoor panel board they have, but being honest 2 600 vac fused discos will be far cheaper.

Another option would be seeing if the motor is rewire able to 240 or 208 volt operation if the poco feeder isn't already set in place. 240 volt 6 space NEMA 3R load centers are a cheap buy.

 

[ActionDave]

You need a pump control panel. They can be purchased with a control transformer that will give you 120V for the timer, pressure switch if you need one, and a HOA for the pump.

 

[Jraef]

You need a pump control panel. They can be purchased with a control transformer that will give you 120V for the timer, pressure switch if you need one, and a HOA for the pump.

And in most cases is available with an SUSE label so that it can be connected right off the meter by itself. Just make sure you ask for that.

 

[pfactor2]

I would make a wild guess that tap rules could apply to two disconnects. I see it frequently done on strip mall services 6 throws and under. I would ask the supply houses to on the smallest 480volt outdoor panel board they have, but being honest 2 600 vac fused discos will be far cheaper.

Another option would be seeing if the motor is rewire able to 240 or 208 volt operation if the poco feeder isn't already set in place. 240 volt 6 space NEMA 3R load centers are a cheap buy.

Unfortunately the closest utility transformer is 277/480. Others 1/4 mile away. I like the two disc. idea. I'm research that. It's legal for sure, just going about the actual work.

 

[pfactor2]

You need a pump control panel. They can be purchased with a control transformer that will give you 120V for the timer, pressure switch if you need one, and a HOA for the pump.

The timer( I don't provide ) actually can be bought 120 or 277 like commercial ballasts . I'm curious though about this panel.

 

[cpinetree]

I have to provide a underground service from FPL to stand alone service for a 277/480 volt, 5HP irrigation motor. The only other load is a irrigation timer. To my knowledge there isnt a small 277/480 outdoor panel available ( like six ckt. so I don't need a main). I'd like to just use a fusible disconnect ( after the meter and before the starter of course ) but what about the timer. Since the fuses will be 15 amp is it legal to tap a phase for the timer? Or any suggestion for the dilemma.

Just a side note: FPL (at least in my area) will require a disconnect before the meter can (Line side of meter) on 480v services.
see FPL Electric standards section IV A 2c (Service equipment rated below 600 volts) link to FPL 2012 standards: http://www.fpl.com/doingbusiness/builder/pdf/Ess4SvcMtrConnect.pdf

On all self-contained metered installations (320 amperes or less) where the service voltage is
480V to ground (2 wire), a non-automatic disconnect device shall be provided and installed
by the Customer on the line side of each individual meter. The disconnect device shall be
lockable or sealable by FPL and adjacent to each meter. The Customer-owned non-automatic (no over current protection) disconnect device ampacity must meet all NEC Guidelines. A lever bypass equipped meter enclosure is required and shall be selected from the Approved Meter Equipment Enclosure List.

 

[kwired]

You need a pump control panel. They can be purchased with a control transformer that will give you 120V for the timer, pressure switch if you need one, and a HOA for the pump.

:thumbsup::thumbsup:

The timer( I don't provide ) actually can be bought 120 or 277 like commercial ballasts . I'm curious though about this panel.

A basic pump panel is just a hybrid combination starter. The standard unit with no additional options is generally a fused disconnect, a magnetic contactor - usually with coil voltage same voltage as the intended supply voltage, motor overload protection, one "hand-off-auto" control switch, and a "start" pushbutton (used for "hand" function starting). They are generally marked as suitable only for use as service equipment, do not have a full size isolated neutral bus as the load generally doesn't require a neutral. They have smaller sized bus commonly like is used for equipment grounding bars for the grounded conductor and it is bolted directly to the enclosure.

Most likely you will find smallest size available is with a NEMA size 1 contactor - will be good for up to 10hp @ 480 volts, but common sizes are also up to NEMA 6 and 7 after that you don't quite have an off the shelf item anymore.

Most of these I have installed are size 4 as most of the crop irrigation here is usually 60, 75, or 100 hp motors, but there are some smaller and some larger.

Options or field add on's could include a control transformer where you could supply your timer from, or a 277 volt timer could tie directly to the 480 volt control circuit.

I would make a wild guess that tap rules could apply to two disconnects. I see it frequently done on strip mall services 6 throws and under. I would ask the supply houses to on the smallest 480volt outdoor panel board they have, but being honest 2 600 vac fused discos will be far cheaper.

Another option would be seeing if the motor is rewire able to 240 or 208 volt operation if the poco feeder isn't already set in place. 240 volt 6 space NEMA 3R load centers are a cheap buy.

Tap rules in 240.21 do not apply to service conductors. Put up to six disconnecting means and make sure the main service conductors are sized to handle the calculated load is all that is required for service "taps".

 

[kwired]

A change in 2014 NEC 210.52, not certain which subsection, calls for 120 volt receptacles at ALL services. This will mean services that supply a single load such as a remote well will now need a 120 volt receptacle installed at the location as well

It will effect irrigation services in this area as they are almost all 480 volt, and the only 120 volt available is usually limited to control circuits with limited capacity.

IMO NEC dropped the ball some on this, at least for this particular application. 120 volts is hardly ever needed for anything, and when it comes to servicing - they people that do much in this particular type of servicing have portable generators on their service trucks, and the power may be needed at the service point or it may be needed 1000 feet away down the center pivot system. Even when doing initial installation, when 120 volt power may be needed the most - by the time you have things ready for operation of the 120 volt receptacle it is generally not needed anymore:slaphead:

Besides, why didn't they put that rule in long time ago, today's cordless tools mean less use of such a receptacle in general anyway.

 

[Jraef]

A change in 2014 NEC 210.52, not certain which subsection, calls for 120 volt receptacles at ALL services. This will mean services that supply a single load such as a remote well will now need a 120 volt receptacle installed at the location as well

It will effect irrigation services in this area as they are almost all 480 volt, and the only 120 volt available is usually limited to control circuits with limited capacity.

IMO NEC dropped the ball some on this, at least for this particular application. 120 volts is hardly ever needed for anything, and when it comes to servicing - they people that do much in this particular type of servicing have portable generators on their service trucks, and the power may be needed at the service point or it may be needed 1000 feet away down the center pivot system. Even when doing initial installation, when 120 volt power may be needed the most - by the time you have things ready for operation of the 120 volt receptacle it is generally not needed anymore:slaphead:

Besides, why didn't they put that rule in long time ago, today's cordless tools mean less use of such a receptacle in general anyway.

Yeah, and UL (around here anyway) has a particular pet peeve about the fact that most of the duplex receptacles sold to mount directly in things like pump panels are technically UL listed only for use on loads INSIDE of the panel (ie things that need wall wart power supplies), not portable power tools that need 120V, because that implies EXTERNAL loads. So if you put them on the back panel or even an inner door as the service outlet, they (UL) bounce the panel builder. That means the only viable solution would be a 120V service receptacle hung on the outside in a WP box of its own, which means now you have an easy access point for the copper thieves to plug in their sawsall without even having to get the pump panel open!

 

[pfactor2]

Just a side note: FPL (at least in my area) will require a disconnect before the meter can (Line side of meter) on 480v services.
see FPL Electric standards section IV A 2c (Service equipment rated below 600 volts) link to FPL 2012 standards: http://www.fpl.com/doingbusiness/builder/pdf/Ess4SvcMtrConnect.pdf

On all self-contained metered installations (320 amperes or less) where the service voltage is
480V to ground (2 wire), a non-automatic disconnect device shall be provided and installed
by the Customer on the line side of each individual meter. The disconnect device shall be
lockable or sealable by FPL and adjacent to each meter. The Customer-owned non-automatic (no over current protection) disconnect device ampacity must meet all NEC Guidelines. A lever bypass equipped meter enclosure is required and shall be selected from the Approved Meter Equipment Enclosure List.[/

 

[pfactor2]

correction

correction

Just a side note: FPL (at least in my area) will require a disconnect before the meter can (Line side of meter) on 480v services.
see FPL Electric standards section IV A 2c (Service equipment rated below 600 volts) link to FPL 2012 standards: http://www.fpl.com/doingbusiness/builder/pdf/Ess4SvcMtrConnect.pdf

On all self-contained metered installations (320 amperes or less) where the service voltage is
480V to ground (2 wire), a non-automatic disconnect device shall be provided and installed
by the Customer on the line side of each individual meter. The disconnect device shall be
lockable or sealable by FPL and adjacent to each meter. The Customer-owned non-automatic (no over current protection) disconnect device ampacity must meet all NEC Guidelines. A lever bypass equipped meter enclosure is required and shall be selected from the Approved Meter Equipment Enclosure List.

Thanks for info, but that FPL standard is for 480 volt 2 wire service. This installation is 277/480 4 wire.

 

[kwired]

Thanks for info, but that FPL standard is for 480 volt 2 Wire service. I wasn't specific , this is a 277/480 volt 4 wire service.

Most places that have such requirements it doesn't matter- if it is over 150 volts to ground regardless of number of phases, they want a disconnecting means on the line side of the meter socket so it can be de-energized before their service tech's do anything in the meter enclosure.

I think it was earlier mentioned that the POCO also wanted a bypass style meter socket which I find kind of pointless, what does the bypass do for you if you are de-energizing anyway? You can't leave lever type bypass in the bypass position and leave it unattended or unguarded either as the lever interferes with putting the cover on when in bypass position.

 

[fmtjfw]

The bypass mechanism in the non-bypass position clamps the meter socket "receptacles".

 

[kwired]

The bypass mechanism in the non-bypass position clamps the meter socket "receptacles".

I am aware of that, I guess that may be one reason to specify that feature even though the "bypass" feature itself is not really necessary.

I have also seen some non bypass sockets with such tight fitting jaws that about make you think you are going to break something trying to insert the meter.

 

[cpinetree]

Thanks for info, but that FPL standard is for 480 volt 2 wire service. This installation is 277/480 4 wire.

A call to engineering will save a lot of time and expense, adding a non-fused disconnect to the line side, after the service is built, would not be fun.