Getting underway on a full rewire.

[theSaltyPuddle]

Hey all. 

I'm about to dive into a new electrical system for my new-to-me Sea Chaser.  I'm using an add a battery system from Blue Sea and the standard Blue Sea components.  I've planning to use the ST Blade Fuse Block - 6 Circuits with Negative Bus and Cover, here are the specs:

Specifications
Circuits   6
Maximum Amperage Maximum amperage ratings are dependent on use of appropriately sized fuses and wire for a given application.   100A per block
30A per circuit
Maximum Voltage   32V DC
Mounting   #8 Screw (M4)
Negative Bus   #10-32 Stud
Positive Bus   #10-32 Stud
Recommended Torque   24 in-lb (2.71 N·m)
Screw Terminal Torque   18 in-lb (2.03 Nm)
Screw Terminal Type   #8-32 Screws with captive star lock washer
Weight   0.55lb (0.25 kg)

From what I can tell, this will adequately handle the load I'm asking it to carry.  Two Scotty electric 1106 model, they each draw 8 amps, a 500gph bilge pump(under 4 amps) and Johnson 5.2gpm wash down pump, which draws 20 amps.  Is there any reason a safety Hub would be any better?  I plan to have a 50 amp circuit breaker in front of the distribution hub.  Obviously each appliance will be fused, as well.

[fishmeister]

I'd suggest double-checking the specs on the motor loads (DR's, bilge pump, washdown pump, etc.).  Regular running current (amps) is only part of the equation.  Suggesting that you check for start-up current as well.  You might need larger circuits to allow for this.

[ohmytodd]

What about your MFD, interior lights, running/anchor lights, VHF radio, USB charger, NMEA2k backbone and any future upgrades you may want to do?

Agreed with double checking everything, and while you've got the hood up you might as well add in extra capacity for later. The safety hub is nice in the stern for things like downriggers and your washdown pump. When I rewired last year I put a safety hub in the stern and a 12 and 6 space fuse block up in the cuddy.

[theSaltyPuddle]

What about your MFD, interior lights, running/anchor lights, VHF radio, USB charger, NMEA2k backbone and any future upgrades you may want to do?

Agreed with double checking everything, and while you've got the hood up you might as well add in extra capacity for later. The safety hub is nice in the stern for things like downriggers and your washdown pump. When I rewired last year I put a safety hub in the stern and a 12 and 6 space fuse block up in the cuddy.

Thanks for the reply.  This is solely for the electrical at the stern.  It will only be two downriggers, 1 wash down pump and a switch for a bilge pump. 

I will be installing another distribution hub behind the helm for two gps/sonar units, 1 bilge pump, VHF radio, navigation lights, windshield wipers, future trim tabs and whatever else may come up. No plans for a stereo,. I'll just use a bluetooth speaker.

[fishmeister]

I'd suggest double-checking the specs on the motor loads (DR's, bilge pump, washdown pump, etc.).  Regular running current (amps) is only part of the equation.  Suggesting that you check for start-up current as well.  You might need larger circuits to allow for this.

Follow up....The starting current for a motor could be anywhere from 125% to 250% of normal running current.

[theSaltyPuddle]

Right.

But isn't the starting current isolated from the distribution hub by the inline circuit breaker?  I was planning to use a 60amp breaker on the line coming from the add a battery.  My plan is to basically wire it the way the add a batter diagram shows, with the exception of adding a second run, one at the stern, one at the helm.  My main engine will be fused with a 150 amp breaker.  I'll be using another 60 amp for the run to the helm.  I feel like I'm missing something here, but not sure how?  My stern power demands are Scotty Downriggers 8 amps each, Wash down 20 amps, and bilge pump under 4 amps.  If everything was running simultaneously I'd see under 40 amps of draw.  I realize that start up of each pulls significantly more juice, but it is highly unlikely all would be running at the same time. 

Thank you for the replies and information. 

[Hydroman]

Right.

But isn't the starting current isolated from the distribution hub by the inline circuit breaker?  I was planning to use a 60amp breaker on the line coming from the add a battery.  My plan is to basically wire it the way the add a batter diagram shows, with the exception of adding a second run, one at the stern, one at the helm.  My main engine will be fused with a 150 amp breaker.  I'll be using another 60 amp for the run to the helm.  I feel like I'm missing something here, but not sure how?  My stern power demands are Scotty Downriggers 8 amps each, Wash down 20 amps, and bilge pump under 4 amps.  If everything was running simultaneously I'd see under 40 amps of draw.  I realize that start up of each pulls significantly more juice, but it is highly unlikely all would be running at the same time. 

Thank you for the replies and information. 

Your Scotty downriggers is greater than 6 amps.

[christianbrat]

1106's are rated up to a 20# ball with an 11 amp draw and a retrieve rate of 185 feet/min compared to the 2106 which is 19.5 amps. Still fine. 2 of them running together is only 20% his capacity. and most people don't use 20# on these 1106s... they use 15 usually