Track 201 Power Planning. David Morschhauser

Transcription

1 Track 201 Power Planning David Morschhauser

2 Overview 1. Power distribution basics 2. DC panel capacity planning example Add a Radar to an existing installation 3. Getting power to an NMEA 2000 backbone and equipment Single source Multiple source

3 Basics +? -

4 Voltage Sources Batteries are always in a state of loosing their charge 12 Volt systems: Use 11 VDC 24 Volt systems: Use 22 VDC 32 Volt (legacy) systems: Use 20 VDC Power supplies provide rated output at a cost Output usually rated 5% to 10% lower than nominal

5 What is the main obstacle to providing the power necessary for a component? Wire Resistance

6 Ohms Law Easy way to remember Ohms Law E is Voltage in Volts Example: Cover I to find unknown Current Formula is I = E/R Example: Cover E to find unknown Voltage Formula is E = IxR I is Current in Amps R is Resistance in Ohms Example: Cover R to find unknown Resistance Formula is R = E/I

7 DC Panel Capacity Planning Calculate existing spare capacity Load of existing equipment Feed wire gauge and length Available spare breakers or fuses If Watts are given, convert to Amps

8 Continuous vs. Intermittent Loads Continuous Loads - Systems that run continuously while vessel is in use. These may include Panel Lighting, Navigation Lighting, VHF Radio on Transmit, Autopilot, Wipers, Depth Finder, Radar, Searchlight, Refrigerator, Engine Electronics. Intermittent Loads - Systems that run intermittently while vessel is in use. These may include Horn, Fresh Water Pumps, Toilet, Trim Tabs, Winches.

9 Calculating Amperage: Step #1 Continuous Loads (12VDC) #1 Get the amperage rating from manufacturer documentation. Using the PIE chart below, you can calculate both Watts and Amps Continuous Loads Amps Watts P / E = I ( E=11V) I x E = P (E=11V) 0.5 Amps 5.5 Watts 5.5 / 11=0.5A 0.5 x 11=5.5W GPS 4 Amps 44 Watts 44 / 11=4A 4 x 11=44W Depth Sounder 1.8 Amps 19.8 Watts 19.8 / 11=1.8A 1.8 x 11=19.8W Navigation Lights 5.5 Amps 60.5 Watts 60.5 / 11=5.5A 5.5 x 11=60.5W VHF Radio Transmit Total Continuous Loads 11.8 Amps Watts SUM of Amps SUM of Watts Power in Watts Voltage in volts Current in Amps

10 Intermittent Loads Horn Trim Tabs Panel Lighting Total Int. Loads 10% of total Int. Loads Largest Int. Load (tabs) Calculating Amperage: Step #2 Intermittent Loads (12VDC) #1 Get the Amperage rating from Manufacturer Documentation. Using the PIE chart below, you can calculate both Watts and Amps Amps Watts P / E = I ( E=11V) I x E = P (E=11V) 3 Amps 33 Watts 33 / 11=3A 3 x 11=33W 12 Amps 132 Watts 132 / 11=12A 12 x 11=132W 0.4 Amps 4.4 Watts 4.4 / 11=0.4A 0.4 x 11=4.4W 15.4 Amps Watts SUM of Amps SUM of Watts 1.54 Amps Watts 12 Amps 132 Watts Power in Watts Use Greatest Value Voltage in volts Current in Amps

11 Calculating Amperage: Step #3 Sum of Continuous & Intermittent Loads Amps Watts Total Continuous 11.8 Amps Watts Largest Intermittent 12 Amps 132 Watts Sum of all Loads 23.8 Amps Watts Conclusion- Panel has 23.8 Amps of total loads

12 DC Panel Capacity Example Install a radar with an existing 40 Amp, 12 VDC panel. We know from previous slide that the panel has 23.8 Amps for existing Loads and a spare breaker position. To find load of the radar, refer to owners manual or literature If you know the wattage is 60W, use 11V to calculate amperage (Amps = 60W / 11V = 5.5 Amps)

13 DC Panel Capacity Example Adding a Radar to an Existing 40 Amp Panel The new radar is rated for power consumption of 60 Watts We calculate that the radar will use 5.5 Amps at 11 V 12V DC Panel I = P / E Amps = 60W / 11V = 5.5 Amps We add 5.5 Amps for new radar to 23.8 Amps for existing Loads and find that the New Total Load is 29.3 Amps 40 Amp Main Total Load = Existing Load + New Load 23.8A + 5.5A = 29.3 Amps 15 Feet 15 Feet 4 Gauge Wire 14

14 DC Panel Capacity Example Adding a Radar to an Existing 40 Amp Panel Panel has 4 Gauge wire 30 feet round trip distance Panel has 40A supply breaker Panel capacity is 40 Amps 12V DC Panel 40 Amp Main Requirements: To New Radar Panel has space for extra breaker Panel has proper amperage capacity Radar less than 10 feet from panel Install 7.5 Amp breaker 15 Feet 15 Feet 4 Gauge Wire

15 3% Voltage Drop Table Refer to NMEA 0400 Appendix C5 (Chart is Conservatively Rated) 3% Drop Current (amps) Distance from source to device (feet) Wire gauge sizes are already computed for round trip Radar Panel 12 Volts /0 1/ /0 2/0 2/ /0 1/0 2/0 3/ /0 2/0 2/0 3/0 3/ /0 2/0 2/0 3/0 3/0 4/ /0 1/0 2/0 3/0 3/0 4/0 4/ /0 2/0 2/0 3/0 3/0 4/ /0 2/0 2/0 3/0 3/0 4/ /0 2/0 3/0 3/0 4/0 4/ /0 2/0 3/0 3/0 4/0 4/0

16 Why Derate Supply Voltage? 20 feet 12 Gage 5 12 VDC About 3% or.36v Current increases to 5.15 amp!!

17 NMEA 2000 Two voltage drop considerations: On the backbone itself Power distribution up to the power insertion point

18 Distribute Power to Backbone

19 Power Distribution: Mid-Powered Backbone Example Termination Resistor 3 LEN 4 Meters Power is traveling left & right POWER 4 LEN 1 Meter 1 LEN 6 Meters 2 Meters 6 Meters 0.5 Meters 0.5 Meters 5 Meters Termination Resistor 2 LEN 6 Meters 2 LEN 2 Meters

20 Voltage Drop Calculations: Why Do We Need Them? Need to ensure that all devices on the network are getting adequate power Device furthest from the power insertion point will have the largest voltage drop May not always be the last device on the network due to drop cable lengths Additional power tees may be required Voltage drop calculations determine this

21 Voltage Drop Calculations: Calculating the Voltage Drop VOLTAGE DROP CALCULATION is Ohms Law; E= I x R E = Voltage Drop (VD) I = Total Network LEN (NL) R = Backbone Length (BL) VD= 0.1 x NL x BL x Cable Resistance Cable Resistance Is in Ohms (Ω) per Meter Lite Cable =.057 Ω / Meter Mid Cable =.015 Ω / Meter Heavy Cable =.012 Ω / Meter

22 Estimated Voltage Drop Calculations: Total Backbone Length & Total LEN 2 LEN 3 Meters 4 LEN 1 Meter 1 LEN 4 Meters POWER Termination Resistor 2 Meters 2 Meters 5 Meters 0.5 Meters 3 Meters Termination Resistor Total BL= 12.5 Total LEN= 10 2 LEN 6 Meters 1 LEN 2 meters

23 Estimated Voltage Drop Calculations: Example from previous diagram NL (Total Network LEN) BL (Total Backbone Length) Cable Resistance-Lite VD (Voltage Drop Estimate) Ω per Meter 0.71 volts E= I x R ( Ohms Law) E = voltage drop (VD) I = total network LEN (NL) R = backbone length in Meters (BL) VD= 0.1 x NL x BL x Cable Resistance VD= 0.1 x 10 x 12.5 x.057 = 0.71 volts

24 NMEA 2000 Backbone Power Treat the backbone just like you would any other product Objective: deliver as much voltage to the backbone as practical Multiple insertion points may be required Source may be battery or power supplies

25 Cables & Connectors: Power Tee Cables Supplies Power to the NMEA 2000 backbone 9-16 VDC Not all Power Tees are the same Different color wires power left & right side of tee Next few slides goes over these specifics

26 Cables & Connectors: Power Tees Numbers on Tee supply Power to a specific side of backbone FEMALE Backbone Connection (some manufacturers) FEMALE Backbone Connection (some manufacturers)

27 Cables & Connectors: Power Tee Wiring-Turck NET-L NET-H Shield / Drain NET-C NET-S Data Wires pass through Tee NET-L NET-H Shield / Drain NET-C NET-S Black : negative White : positive Grey : shield / drain Blue : negative Brown : positive Grey : shield / drain Must fuse at supply ends

28 Cables & Connectors: Power Tee Wiring-Molex NET-L NET-H Shield / Drain NET-C NET-S Data Wires pass through Tee NET-L NET-H Shield / Drain NET-C NET-S Blue : negative Brown : positive Grey : shield / drain Black : negative White : positive Grey : shield / drain Must fuse at supply ends

29 Cables & Connectors: Power Tee Wiring- Actisense NET-L NET-H Shield / Drain NET-S NET-C - Data Wires pass through Tee Data Wires pass through Tee + NET-L NET-H Shield / Drain NET-S NET-C Red + Black - Grey : shield / drain Red w/ stripe + Black w/ stripe - Grey : shield / drain Must fuse at supply ends

30 Cables & Connectors: Power Cable- Garmin Different than all others Tee is not molded Connects into a standard Tee connector 3 Amp only- Parallel Red + Black Shield / Drain (bare)

31 Seldom Considered Field attachable connector Micro-style easily handles #14 AWG conductor Previous examples match power pair size in Lite backbone cable (#22) Also, can be fused to 4 amps to match Mid cable capacity

32 Also Undervalued (Because of $$$) Combines redundant power supplies (or AC with a DC) Houses fuses Power indication Clamps backbone voltage at 16 VDC

33 Simple Multi-segment

34 More segments Shield/Drain left unconnected at all other insertion points Add lead to tie power supply grounds together

35 Questions?