TAP and GATEWAY Communication Cable Installation

This article discusses the requirements for the data cable that connects the TAP (or Gateway), to the Data Logger (CCA, Cloud Connect or MMU). The cable is Dark Blue. The wire colors shown are not correct as they are for a non-twisted pair type cable, which is not supported.

Tigo's TAP and Gateway devices both serve the same function of providing wireless communictions to the MLPE. The TAP is the latest generation. To identify which device you are using, see TAP vs Gateway (as Gateways use a different connection method)

Contents: 

1. TAP Communication Cable Requirements
2. Recommended Cable Types
3. Maximum Cable Length Recommendations
4. Using Ethernet Cables (Cat 5 / Cat 6)
5. Installation Tips!

TAP/Gateway Cable Requirements

ALWAYS CHECK THE PRODUCT dataheet for exact and current specificatons
TAP Datasheet

Recommended cable type: RS485, 18-22AWG

The connection from Data Logger (MMU, CC or CCA) to a TAP (or Gateway) requires a 2 twisted pair cable, or a  cable with at least one Twisted Pair (TP) to be used on the A and B connections

This cable can be RS-485 rated (preferred), and shielded or not.

The data communication cable must have these features:

• At least 1 Twisted Pair (TP) of wires (for A and B connections)
• Smallest supported wire size is 22 AWG (0.33 mm²)
• Max cable Outside Diameter (OD) of 0.35 inches / 9.0 mm (so it will fit inside the cable gland)

Recommended Cable Types

1. 2 twisted-pairs (shielded preferred) RS-485 rated
2. Ethernet Category 3 or above can be used for shorter distances, see table below.
3. Longer cables as needed on commercial systems (with any TAP more than 100 feet from CCA) should only use of RS-485 specification cables only, not Ethernet.

These cables are manufactured in 2 shielding types:

• UTP - Unshielded Twisted Pair 
• STP - Shielded Twisted Pair 

1. Either ehield type can be used
2. STP cable is highly recommended. Especially, if the wiring is not housed in conduit and/or located near an HVAC electrical motor or radio broadcast equipment.
3. Anything that can create a strong electromagnetic field can cause interference on a non-shielded cable and this will affect the data signal.
4. If the cable is not housed in a conduit, please use an outdoor-rated (UV resistant) cable for UV resitance protection.
5. Remember to check with your Authority Having Jurisdiction (AHJ) to see if there are any local requirements for cabling on your project.
6. Can cable be in conduit with Home Run?

Compliant Cables:

RS-485 Compliant

Ethernet Category 5e U/UTP, CMP

Ethernet Category 5e, U/UTP, CMR

Omni Cable's 600V 18AWG 2-Pair Tray Cable, P/N L21802

Maximum Cable Length

The length of a cable determines its resistance

The table (below) provides the maximum length recommendations for data communication cables, based on the wire gauge and the number of TAPs.

1. Wire sizes are listed in American Wire Gauge (AWG) and Millimeters (mm).
2. Wire Lengths are listed in Feet (ft) and Meters (m). 

Using Ethernet Cables (Cat 5 / Cat 6)

Multi-lead cable (like Cat 5 / Cat 6) may require that the installer combines wire Pairs and/or Triplets. Here are some guidelines for Ethernet cable usage that will help maintain a quality signal and deliver full power to all the TAPs on the system. 

1. Use 1 Twisted Pair for the A and B wires. These wires must both be from the same pair, not from different pairs.
2. To reinforce the 24V DC Power send, combine duplicate pairs or triplets of the remaining leads.
   (This can be helpful for distances over 100 feet, or on systems with 2 or more TAPs.)

For commercial systems:Use of Ethernet cable is strongly discouraged due to the longer cable lengths needed in commercial application, combined with the number of TAPS per CCA. For these reasons, Ethernet (Cat 5 / Cat 6) cables may not meet the minimum requirements needed for cable length and mitigation of signal interference.

STEP 1 for use of 22 AWG ONLY on the IDC (punch-down) terminals. Remove 1.5 inches of the outer jacket.   Be careful to not nick or damage the insulation on the internal wires. If damage occurs, cleanly cut the cable-end, and start again
STEP 2.  Open the cover.   The Red Arrow is pointing at the provided connector that must be used for 20 or 18 AWG.   NOTE this example does not have the required end of chain  resistor installed between A and B on the right hand side connedto. Opening and Closing the TAP.
STEP 3.  Remove the Wire Connector, if using IDC terminals.   Using a flat head tool or blade, insert underneath the connector, and gently rotate it clockwise, and counter clockwise, until it loosens from the PCB terminals.
STEP 4. Unscrew the Cable Gland at the bottom of the TAP, and feed the cable through. This can be done before or after you have removed the outer sheathing (STEP 1).
STEP 5.1 (Terminal Method, MUST be used when combining pairs for power) Strip the outer jacket 1.25 inches Strip the wire 3/8 of an inch. If needed, loosen the srcrews until there is space for the wire. Inserting the wires into the connector, and tighten them until a firm tug does not remove them. NOT so tight to cut/break the wire. This example is using Ethernet cable with non-standard pair scheme for the power connection. Take a picture or write down what wire colors were used for which terminal, for use at the Data Logger. When you have completed attaching the wires, press the terminal back onto the pins (located on the TAPs board).
STEP 5.2 (IDC Method) Remove outer jacket Lay the unstripped wires to their terminals Use a punch-down tool or small screwdriver, press the wire down until it is in the bottom of the notch. Note: Since the IDC connector cannot take multiple wires, the maximum wire length is affected. This limits the number of TAPS to 2.
STEP 6 Tighten the Cable Gland, by turning it clockwise (righty tighty). Make sure it's firmly tightened, to prevent water entry. Then, close the TAP, and attach to the frame of a module with Cable Glands facing downward (to discourage water from following the cables, into the Glands).

Installation Tips!

Conduit and Cable Trays: 

When running the communication cable in the same conduit as an energized PV String Wire (home-run lead), use a cable that has a 600 VDC insulation rating. This will eliminate the need for the installation of a separate conduit for the communication cable, especially in systems where the string voltage will never exceed 600 VDC. Ehternet cable is normally rated to only 300 VDC.

When installing multiple TAPs (or for longer distance runs):

Longer distance runs, requires more consistent power. To provide consistent or unbroken power, try wiring in twisted triplets. 

For example: With an Ethernet cable (Cat 5 / Cat 6), combine 3 individual wires for the "+" (positive), and 3 for the "-" (negative) posts. The B and A posts do not require additional wires. 

NOTE: This will only work when using the screw-top terminal brick connector, as multiple wires will not fit in the quick-punch IDC terminals.

A resistor is pre-installed on the right-hand side terminals on each TAP. It is connected to the A and B terminals, which are the RS-485 data signals. Remove the resistors from the multiple TAPs along the daisy-chain. When you get to the last TAP in the chain, it must have the resistor inserted in the outgoing A and B terminals.

Mounting the TAP:

The TAP is designed to be installed under a panel, not out in direct sunlight. Tigo recommends installing the TAP on the frame of a panel, not in an attic or other radio signal decreasing barrier.

The TAP connects to the PV-Module frame using the mounting bracket. Mount the TAP with the label side outward (facing away from the panel). If the PV-Module has no frame, the holes of the brackets can be used to screw them to a panel racking system.

The signal radiates horizontally to the sides, not towards the sky or ground, so install it near the center panel of the array whenever possible.

For full installation directions, see page 12 of the TAP Installation Manual.

Testing the TAPs: 

After installation is complete, the Discovery portion of the commissioning process should find all of the TAPs, quickly. If the Discovery reports fewer TAPs than configured on the Equipment page, run a Gateway Test. You can do this by using the Tigo Energy Intelligence App installed on your phone/device. See section #3 Confirm Network.

For legacy equipment (Tigo Cloud Connect and MMU), you can do the test using the buttons on the control panel for: 2.5. Gateway Test. https://support.tigoenergy.com/hc/en-us/articles/208746708-Cloud-Connect-MMU-Menu-Reference