AC Electric System

April 25, 2015

 

The AC electric system is the standard European 220V, 50Hz.

There are three sources of AC power:

  1. Shore power
  2. Generator
  3. Inverter

No part of the AC electric system is connected to the boat hull except for one grounding point on the port engine.

 

Procedures

Connecting the Shore Power Cable

  1. Turn the source selection switch on the AC source selection panel to 0.
  2. Connect the shore power cable at the boat first, then at the shore.
  3. Check the shore power voltage and frequency on the AC source selection panel.  Voltage must be 220 V (+ - 5%), frequency must be either 50 or 60 Hz, depending on country.  Do not switch to shore power if the values are off.  Damage to equipment or fire may result.
  4. Turn the source selection switch on the AC source selection panel to shore power.

Disconnecting the Shore Power Cable

  1. Turn off all AC users on the branch circuit panel.  Ampere meter on the AC source selection panel must show 0.
  2. Turn the source selection switch on the AC source selection panel to 0.
  3. Disconnect the shore power cable at shore outlet first.
  4. Close shore power inlet cover tightly.

Switching AC Power Source

Before switching AC power source make sure that all the branch circuit breakers are off and that the Ampere meter on the AC source selection panel shows 0.

Troubleshooting.  No Shore Power

If the shore power cord is plugged in and there is no power available at the AC panel, check the GFP breaker on the shore power panels, located near the shore power inlet in the forward section of the starboard hull or in the starboard engine room entrance.  It is easy to forget their existence.

Log

2015

April  16

The breakers for the bridge and the nearby water heater break while using
the pressure washer.  Overheated?
   

 

Equipment

AC Rack Panels

The AC rack panel seen from the back.

 

AC Source Protection and Selection Panel

The AC source protection and selection panel is a standard 19" rack panel and is located at the bottom of  the AC rack of the wheelhouse.

The three sources are protected by circuit breakers.

The transfer between power sources is made with a device that prevents arc over between the contacts of the different sources.  Special care must be taken to prevent arching between shore power or generator power and the inverter, since such arching would immediately destroy the inverter.

Each AC power source is protected by a circuit breaker with GFP.  Each breaker is calculated so as to match the maximum power available from the source.  The shore power is thus protected twice to abide by the rule that there must be a breaker within 3 meters of the shore power connector.

Source Protection Circuit Breakes Max. kW (220V) Breaker A
     
Shore power 3.5 16
Generator 10 32 
Inverter 1 16

 

AC 2

1

19" AC source protection rack panel    
3 Circuit breakers with GFP bticino Btdin 45 G8813A  

 

1

19" AC source selection rack panel    
3 Volt meters Datel DMS-20-PC-1-LM/a www.datel.com
3 Frequency meters Datel DMS-20-PC-3-FM www.datel.com
1 Digital ampere meter AMTD-1 ABB 2CSM320000R1011  
1 Digital volt meter    
1 Rotary transfer switch Bremas  
4 Source indicator lamps, 220 V    

 

 

AC Branch Circuit Panel

The AC branch circuit panel is a standard 19" rack panel and is located in the AC rack of the wheelhouse.

All circuit breakers have GFP, ground fault protection.  The circuit breakers are rated at less than the ampacity of the smallest current-carrying conductor in the circuit.

AC 3 


  Max. kW (220V) Breaker A Wire size mm2
       
Port cabin and bathroom outlets 3.5 16 2.5 
Starboard cabin and bathroom outlets 3.5 16 2.5
Bridge and flybridge outlets 3.5 16 2.5
Dinette outlets 3.5 16 2.5
Kitchen outlets 3.5 16 2.5
       
Port and Starboard hull lights 3.5 16 2.5
       
Cook top 6.2 32 4.0
Dishwasher 3.5 16 2.5
Refrigerator and Freezer 3.5 16 2.5
       
Washer - dryer 3.5 16 2.5
       
Water heater 1.54 16 2.5
       
Battery chargers each 3.5 16 2.5
Navigation computer 3.5 16 2.5
Air conditioning and heating   32 6.0

 

19" AC branch circuit rack panel    
15 16 A Circuit breakers with GFP bticino Btdin 45 G8813A   
2 32 A Circuit breakers with GFP bticino Btdin 45 G8813A   

 

AC Branch Junction Box

The AC branch junction box is located in the space below the wheelhouse, in the starboard hull above the fuel tank.

The relays control all the hull lights.  They are all 12 V AC, with the 12 V provided by a small transformer beside them.

The wires that go from the branch circuit panel on the rack to the branch junction box are numbered in the following way.

  #
Cook top 1
Air conditioning, heating 2
Dishwasher 3
Washer - Dryer 4
Refrigerator - Freezer 5
Kitchen outlets 6
Dinette outlets  7
Navigation Computer 8
   
Battery charger starboard 9
Water heater port hull 10
Battery charger port 11
   
Cabin and bathroom outlets, port 12
Cabin and bathroom outlets, starboard 13
Hull outlets 14
Hull lights 15


 

1

Fiberglass box, 405 x 600 mm Gewiss series 46 QP   
9 12 V AC dual pole latching relays Hager 521  
       

 

 

Shore Power Panel

The main shore power panel with GFP is located in the starboard front compartment.

In Europe, with 220V, usually the shore power has a capacity of 30A.  In the US, with 117V, the shore power has a capacity of 30 A.

AC 1 

 

A permanent waterproof warning placard of notice must be displayed prominently at the shore power inlet.

ABYC suggests the following wording:

 

 

 

 

 

 

 The maximum unprotected conductor length from shore-power inlet to circuit breaker must not exceed 3 meters.  The circuit breaker must be rated at no more than 125% of the primary rating of the insulation transformer (ABYC).  

The shore power connector and the main shore power disconnect circuit breaker with GFP have an ampacity of 30A.

1

Insulated panel    
1 Circuit breaker with GFP bticino Btdin 45 G8813A  
1 Non metallic boat inlet Marinco #301 EL-B  

 

AC Hull Lights

In the hulls there is an AC fluorescent light in the engine entry rooms, engine rooms, above the fuel tanks, two each in the hulls besides the cabins and in the bow section.  The lights are switched on or off with relays situated in the branch junction box. 

10

Fluorescent lamp holders, 18 W  disano echo hydro 18W  
10 Fluorescent lamps    

 

Insulation Transformer

The insulation transformer and voltage selector are located on an insulated panel under the wheelhouse.

Isolation transformer schematic

The circuit up to and including the insulation transformer is electrically insulated from the boat. The frame of the transformer is grounded to the shore ground but otherwise insulated from the boat.  It is very important to interrupt the shore power grounding wire, which otherwise might provide a path for stray corrosion currents between boats sharing the same shore power circuit.

The insulation transformer has two primary voltages, 110V and 220V, and one secondary voltage of  220V, enabling the boat to operate either in the United States or Europe (taking into consideration the different power frequencies).  The voltage selectors are located on the transformer, since the switching is done only in rare occasions and a mistake could possibly fry the transformer and other equipment.

The isolation transformer, on the primary side, also takes care of stepping up the American 110V to 220V.
On the secondary side the output is 220V.
The  transformer operates for both 50 and 60Hz.
The insulation transformer has an ampacity of 30A.

Isolationg Transformer Connections

Trasformatore monofase di isolamento SER:TMI
Norme CEI EN 61558-2-4
5KVA 50/60 Hz  ta 40 gradi C. classe B
PRI 110 V   SEC 220V  25 A
Collaudo Data 26  1007 - CA Prod. 4709

Purchased January 2008 from AGF electronics, Albizzate.

Insulation transformer ELCA srl

ELCA srl
Cerro Maggiore (MI) Italy
Phone +39 0331 576 229

The following manual provided by the manufacturer is also part of this section:

AGF Insulating Transformer Manual

 

Inverter

The inverter is located above the port fuel tank.

It is an AGF model IST4.  It has a continuous output of 220 V and 1000 W but can output 3000 W for a few seconds.

Input 10 to 16 V DC.
Output sinusoidal, stabilized between +/- 0.1%, 50 Hz.

Does not draw any current when there is no AC load.

1

AGF inverter AGF model IST4  

AGF Electronics
Caronno V.

The following manual provided by the manufacturer is also part of this section:

AGF Electronics Inverter Manual

 

Hardware

Circuit Breaker with GFI

Bticino C16   I delta n 00.03A

Circuit breaker with GFP bticino BTDIN GC8813AC16

BTicino

The following data sheet provided by the manufacturer is also part of this section:

Bticino GFI instruction sheet

 

Ampere Meter

The digital ampere meter is a standard panel meter.  It can measure loads up to 100 A.

It consists of the meter itself and of the actual measuring transformer through which goes the wire that carries the current to be measured.

The transformer has a ratio of 100/5 A, kV 0.72-3

Purchased September 2008

Digital ampere meter AMTD-1 ABB 2CSM320000R1011
Transformer Type AC 32 N 0441TA FRER Italy 1TAC032100-05

ABB

The following data sheet provided by the manufacturer is also part of this section:

ABB digital meters data sheet

 

Volt Meter

The digital volt meter is a standard panel meter.
Maximum voltage 600 V AC-DC

Purchased Spring 2009

Digital voltmeter VLMD-1 ABB 2CSM320000R1011

ABB

The following data sheet provided by the manufacturer is also part of this section:

ABB digital meters data sheet

 

Frequency Meter

The digital frequency meter is a standard panel meter. 
Frequency range 35 ... 400 Hz

Purchased Autumn 2014

Digital frequency meter FRZ-DIG ABB 2CSM710000R1011

ABB

The following data sheet provided by the manufacturer is also part of this section:

ABB digital meters data sheet

 

 

AC Wires

All AC wires are the "gray", double insulated wires, type FG7OR (sheath in PVC, insulation rubber, does not propagate fire), with brown or black phase, blue neutral and green and yellow ground.

They are flame retardant, in line with table A.1 of ISO 13297 and protected according to their rated current carrying capacity as indicated in the table.


Wires of the following sizes are used:  0.75, 2.5,  4 and 6 mm2.
The 0.75 mm2 wire is for the switches.

The ampacity for the wires was calculated using the CEI Manual tables.
For the wires that will pass through the engine rooms the size calculation considers a room temperature of 60 degrees C.

 

AC Wire Harnesses

Main Harness

The main harness goes from the branch circuit panel on the rack to the branch junction box above the fuel tank on the starboard side.

Aft Harnesses

The two harnesses go from the starboard branch junction box above the fuel tank to the aft of the boat, that is to the engine rooms and engine rooms entrance. The wires follow the outside hull panels. The port harness crosses the boat under the bridge.
There is only one wire in each harness for the AC outlets, with waterproof junctions at each outlet.

  Load A Size mm2
Engine room entrance light(fluorescent) 0.1 2.5
Engine room entrance light switch -

2 x 0.75

AC outlet - -
     
Engine room light (fluorescent) 0.1 2.5
Engine room light switch - 2 x 0.75
AC outlet 6 2.5
Above tanks light (fluorescent) 0.1 2.5
Above tanks light switch - 2 x 0.75
AC outlet 16 2.5

Forward Harnesses

The two harnesses go from the starboard junction box above the fuel tank to the forward of the boat.  The wires follow the outside hull panels. The port harness crosses the boat under the bridge.
There is only one wire in each harness for the AC outlets, with waterproof junctions at each outlet.

  Load A Size mm2
Forward hull lights ( fluorescent) 0.2 2.5
Forward hull lights switch - 2 x 0.75
Water heater or equivalent 16 2.5
AC outlet 16 2.5
Forward bulkhead lights (fluorescent) 0.2 2.5
Forward bulkhead light switch - 2 x 0.75
AC outlet - -
Cabin and bathroom outlet 16 2.5

Kitchen Dinette Harness

The harness goes from the starboard junction box above the fuel tank and proceeds under the bridge to the various locations.

  Load A Size mm2
Washer - dryer under bridge 16 2.5
Cook top and oven 32 6
Refrigerator and Freezer 16 2.5
Dishwasher 16 .5
Kitchen outlets 16 2.5
Dinette outlets 16 2.5
Computer 16 2.5

 

Bridge-Flybridge Harness

The harness goes directly from the branch circuit panel on the AC rack to the various locations.

  Load A Size mm2
Bridge and flybridge outlets 16 2.5

 

Air Conditioning Heating Harness

The harness goes from the starboard junction box above the fuel tank and proceeds under the bridge to the bridge air handler, and from there to various air conditioning and heating locations.

  Load A Size mm2
Air conditioning main power 32 6

 

2015-04-25
cat_07_e ac electric system.htm