Revision: 8
Rev date:11/04/2011
Author:Ethan Howard
Keywords:Net Hatchet, Heavy Duty, Relay, Instructions, Wiring, Configuration, Appliance
Abstract
The Net Hatchet’s onboard relay can handle quite a few DC applications but occasionally the need arises to control something running on AC power or higher current DC. In these situations the Net Hatchet can be configured to drive a heavy duty relay designed to handle the higher loads.
The Net Hatchet onboard relay is able to handle 1.2A at T=25C, (0.9A at T=60C). The coil current of most relays is less than 1A. Many draw between 100mA and 200mA. The Net Hatchet will not have trouble sinking enough current to operate larger relays. It is important to note that the Net Hatchet can only power a 5V coil, (using the + Fan pin). When controlling AC power from the wall, you need to select a relay that can be triggered by 5V. If you are switching a DC device (less than 60V) you also have the option of borrowing power for the coil from the same source.
Full Text
The following set of instructions describes how to correctly wire up a high current relay to the Net Hatchet. This type of configuration is used for controlling higher current DC devices or AC lines.
1. Read the entire instruction set before starting making sure you understand each step. This reduces the chances of an action causing problems with a future step, or premature failure of the device.
2. Unplug the Net Hatchet from power. (Check both the DC jack and the POE port.) Failure to disconnect the Net Hatchet from power could result in equipment damage or electric shock. Make sure all other systems you are interfacing with are also disconnected from power.
3. Gather the items listed below.
• Net Hatchet
• Wire Cutter
• Wire Stripper
• Relay
o (DC) Mouser part # 558-DC60S5 $24.35
o (AC) Mouser part # 881-STH24D12 $15.86
o Other relay suited for the application
• Wire (of suitable gauge)
• Soldering Iron (optional)
• Any additional connectors required by the relay
4. Note: Steps 5 through 11 are for the configuration with the relay being powered by the Net Hatchet. This configuration is for AC systems and DC systems with a 5V relay. If are working with a DC system that is providing the coil power itself, please skip to step 12.
Steps 5 – 11: The Net Hatchet provides coil power. For AC systems and DC systems with a 5V relay.
5. Clip one conductor of the AC extension cord with the wire cutter. Where you cut will depend on how the equipment will be mounted. It is not advised to clip closer than 6 inches from either end of the cable so that you have room to work.
6. Carefully separate the two conductors from each other on both halves of the wire. (This may require a CAREFUL clip with wire cutters between the conductors.) Strip the shielding back on both ends approximately one half inch. Figure 1 shows the cord with the conductors separated an appropriate distance and the insulation stripped back. (This cable had both conductors cut but it has been repaired.)
7. Connect a wire from the “fan+” pin on the Net Hatchet to the relay coil. (White wire in Figure 2.) Some relays do require polarity on the coil side. It is important to make sure the coil is hooked up as per the manufacturer specifications.
8. Connect a wire from the “relay+” pin to the other side of the coil. (Blue wire in Figure 2.)
9. Jumper the “relay-“ pin to the “gnd” pin. (Black wire in Figure 2.)
10. Connect the AC extension cord to the relay. The plug half of the cord should be connected to the relay common terminal. The receptacle side of the cord should be connected to the relay normally open terminal. Figure 3 shows the completed configuration.
11. Connect the Net Hatchet to power and login via the web interface to configure the relay controls. Your Net Hatchet is now ready to control high power devices. Figure 4 is the electrical diagram to aid in comprehension of this configuration.
Steps 12 – 18: The external system provides coil power. Not for use with AC system.
12. Connect a wire from the supply of the DC system (in this case a battery bank) to the relay common terminal. (Orange wire in Figure 5.)
13. Connect a wire from the supply of the DC system to the relay coil. (Orange wire in Figure 5.) Some relays do require polarity on the coil side. It is important to make sure the coil is hooked up as per the manufacturer specifications.
14. Connect a wire from the “relay+” pin to the remaining coil contact on the relay. (Green wire in Figure 5.)
15. Connect a wire from the “relay-“ pin to the ground of the DC system. In this case, the negative terminal of the battery bank. (Blue wire in Figure 5.)
16. Connect a wire from the relay normally open contact to the supply of device you are controlling. (Disconnected red wire in Figure 5.)
17. Connect a wire from the DC system ground to the ground of the device you are controlling. (Disconnected blue wire in Figure 5.)
18. Connect the Net Hatchet to power and login via the web interface to configure the relay controls. Your Net Hatchet is now ready to control high power devices. Figure 6 is the electrical diagram to aid in comprehension of this configuration.
