BLUE SEA SYSTEMS Automatic Combiner Relay

Electrical and electronic topics for small boats
jimh
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BLUE SEA SYSTEMS Automatic Combiner Relay

Postby jimh » Mon May 23, 2016 1:22 pm

(This article is an update of one I wrote six years ago. The prices have all gone up, so I thought it appropriate to revise the article.)

Blue Sea Systems makes a nice automatic combiner relay or ACR (which they now call an automatic charging relay), their model 7610, and its retail price is about $110. I was investigating this product for possible use on my boat, and I read the installation instructions:

http://bluesea.com/files/resources/inst ... 310020.pdf

It struck me as odd that the device requires installation of fuses in every one of the five circuits that connects to it, yet the device itself does not provide for any of these fuses. I'd expect that if the device requires five fuses, the design of the device would have incorporated five fuse holders in the device itself.

Adding all the required fuses will add considerably to the cost of the installation. The main connections between the batteries and the ACR require a fuse in each leg with a minimum rating of 80-amperes and a wire conductor size of 6-AWG. A suitable device from Blue Sea would be their 5006 80-Amp MaxiFuse connector. Two will be needed, along with two 80-ampere fuses. The other three fuses can be simpler, less expensive, in-line fuses.

Added Parts:

2 x Blue Sea 5006 MaxiFuse connector; $29.21-each
2 x 80-ampere MaxiFuse; $3.27-each
3 x In-line Waterproof ATC fuse holder; $9.88-each
3 x ATC fuses, 2-ampere, 10-ampere: $1.09--each

COST = $98

In addition, installation will require a great deal of terminal connectors:

8 x 6-AWG ring terminals; $3.50--each
12-miscellaneous butt splices and ring terminals; $0.75-each

COST = $37

We also need quite a bit of new wire to install the device:

2-feet 6-AWG; $4
25-feet 16-AWG; $12

COST $16

These added costs now total $151, which is actually more than the ACR device itself cost. If you are planning to install an automatic combiner relay, it may be useful to take into account all of the additional components recommended for installation, to order them in advance, and to consider their cost as part of the project cost.

It looks like just the parts for this project will cost about $260 at retail. Like everything, you can certainly find some vendors selling these parts at lower costs. But for making a comparison, providing a comprehensive summary of what will be needed, and to be consistent I have used the manufacturer's prices .

I previously compared these components and prices several years ago. At that time the total cost was about $175. In this new comparison I upgraded the in-line fuses to the ATC waterproof holders, as that style provides for simple mounting to a bulkhead instead of leaving the fuse holder hanging in mid-air. The costs of marine electrical wiring devices has risen in six years since I first looked at this project

robb28
Posts: 3
Joined: Sun Mar 20, 2016 2:29 pm

Re: BLUE SEA SYSTEMS Automatic Combiner Relay

Postby robb28 » Mon May 23, 2016 10:03 pm

Great notes Jim. Some of these costs caught me by surprise when I recently completed a similar project.

I had good success using www.genuinedealz.com for some of the components and some custom wire. Notably, some of their Blue Sea prices were even cheaper than Amazon

jimh
Posts: 11673
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
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Blue Seas Model 7610 Automatic Combiner

Postby jimh » Tue Apr 26, 2022 9:56 am

[I again update this article to reflect the prices for the Blue Sea Systems components at their 2022 MSRP costs. For the other components (wire and terminal connectors) I left the prices as in the 2016 revision above. Those prices may be at lower cost than could actually be found in 2022, depending of what vendor was used. The original 2010 article is still archived.--jimh]

Blue Sea makes a nice automatic combiner relay, their model 7610, and its retail price is only about $125. I was investigating this product for possible use on my boat, and I read the "full installation" instructions:

https://d2pyqm2yd3fw2i.cloudfront.net/files/resources/instructions/990170140.pdf

It struck me as odd that the device requires installation of fuses in every one of the five circuits that connects to it, yet the device itself does not provide for any of these fuses. I'd expect that if the device requires five fuses, the design of the device would have incorporated five fuse holders in the device itself.

Adding all the required fuses will add considerably to the cost of the installation. The main connections between the batteries and the ACR require a fuse in each leg with a minimum rating of 80-amperes and a wire conductor size of 6-AWG. A suitable device from Blue Sea would be their 5006100- MaxiFuse connector. Two will be needed, along with two 80-ampere fuses. The other three fuses can be simpler, less expensive, in-line fuses.

Added Parts:
  • two Blue Sea 5006100 MaxiFuse connector; $32.50-each
  • two 80-ampere 51543 MaxiFuse; $6.70-each
  • three in-line waterproof 5061 AGC fuse holder; $7-each
  • three AGC fuses, 2-ampere, 10-ampere: $2.50--each
  • COST = $107

In addition, installation will require a great deal of terminal connectors:

  • eight 6-AWG ring terminals; $3.50--each
  • 12 miscellaneous butt splices and ring terminals; $0.75-each
  • COST = $37

We also need quite a bit of new wire to install the device:

  • 2-feet 6-AWG; $4-per-foot
  • 25-feet 16-AWG; $12
  • COST = $20

These added costs now total $164, which is actually more than the ACR device itself cost ($125). This brings the cost of "full installation" of the 7610 to be around $289. Those costs are at MSRP, and some savings may be possible from reduced prices offered by vendors.

Looking at the original 2010 MSRP for the 7610 at only $70 and comparing to the 2022 total installation cost of about $289, the cost of adding this product has increased by a factor of more than four in just 12 years.

Note: The 7610 Combiner Relay is sold in a bundle with the 5511e Two-Circuit Battery Switch as the 7650 "Add a Battery" kit. The MRSP for the Model 7650 bundle is $188. See

https://www.bluesea.com/products/7650/A ... Kit_-_120A