Backup Gateway

Backup Gateway Guts

**Key Points**

• The Backup Gateway 2 functions as an automatic transfer switch to manage a residential electrical system.  

• It can disconnect all downstream loads from the grid and signal the Powerwall to create a microgrid.  

• Systems can be configured for either whole-home backup or partial-home backup.  

• Large loads, such as water pumps and air conditioning units, can be excluded from the backup circuit.  

• The internal panelboard kit is an optional accessory that eliminates the need for a subpanel.  

• The Backup Gateway can serve as the main service disconnect for the site when used with an Eaton CSR or BW breaker rated between 100-200 Amps.  

• The neutral bonding strap must be removed if the Gateway is **not** acting as the main service disconnect.  

• The non-backup lugs support up to 100 amps.  

• Meter X has embedded CTs that measure the supply feed.  

• Meter Y uses 100 Amp Auxiliary CTs and can be used for monitoring solar, site loads, or conductor performance.  

• A low-voltage switch (RPSD) can be installed to disable all Powerwalls paired with the Gateway.

Auxilary CT metering

Plug the Auxiliary CT connector into the port at the top of the unit.

Keep in mind that the left most port is L1, the middle is L2, and the rightmost is L1.

Things to Look out for when installing and auditing

• Metering is critical to the function of the Powerwall system

• The Backup Gateway contains two meters.

• Meter X monitors the supply connections through embedded CTs

• Meter Y can be configured to monitor various sources with Auxiliary CTs.

• Site, Solar, Solar 1x2, Conductor, or Load Monitoring is available

• Auxiliary CTs can be extended up to 330ft

• Auxiliary CTs are rated up to 100 Amps.

• Auxiliary CT ports default to L1, L2, and L1 respectively.

• Always plug CTs into the port at the Gateway before clipping them around a de-energized conductor.

• If Meter X and Meter Y cannot monitor the entire site, a Remote meter will need to be added.

• Auxiliary Meter Y equipment is NOT cross compatible with Remote metering equipment.

Note: that Auxiliary Meter Y equipment is NOT cross compatible with Remote metering equipment.

Note: Installers can run a heavy load (like a plug in drill) to confirm the CTs are performing correctly

Generation Panel

The Backup Gateway comes with 2 sets of backup termination lugs, and one set of non backup termination lugs. These lugs can be used to feed new or existing downstream electrical panels.

One set of lugs can also be used to feed the optional internal panelboard kit, removing the need for a subpanel.

Solar and Powerwall can be added to the generation panel downstream of a 200A disconnect. NEC article 705.12 (d).

Neutral Bonding Strap 

Integrated Tesla Metering

Gateways need to monitor the following:

• All energy flowing from the utility meter.

• All solar generation

• Downstream generators if applicable

• Conductor export limits if applicable

In most cases, site energy flow will be monitored by the embedded Meter X CTs, and solar inverters can be monitoring with the Auxiliary Meter Y CTs. Energy metering will be covered in depth in later trainings.

PARTS

Optional Internal Panelboard Accessory

The internal panelboard accessory can be installed inside of the Gateway 2 and removes the need for a subpanel to house generation sources or relocated non-backup loads. The Panelboard can be configured to the line or load side of the relay (backup or non-backup).

• 6/12 Space Eaton Type OPD

• 200A capacity for Backup

• 100A capacity for Non-Backup

Note: The panelboard must be used exclusively for backup, or exclusively for non-backup.

Mounting Gateway

• Take the deadfront off the front of the Gateway

• Determine whether cable entry to the Backup Gateway will be from the top, bottom, rear or side of the enclosure. Knockouts are 3/4" trade size and can be expanded up to 2".

  • NOTE: If we need to configure the Backup Gateway for cable entry from the top, do the following: 

  • Remove the top entry plate.   

  • Install the 2" or 1 & 1/4" top entry hub with the included screws.

  • Use a reducing bushing if your conduit is smaller than the hub

• Install the (4) mounting screws into studs that can support the weight.

Semi-Flush Mounting

The Backup Gateway 2 can be semi-flush mounted, with a maximum depth of 4.25". This is to ensure the door swing does not interfere or contact the mounting surface.

ELECTRICAL
Note: When wiring the unit, work from the back of the enclosure towards you. This will make it easier to land conductors and cleanly route them through the unit. Plan your conductor routing to avoid difficult wire bending.

• Connect the supply conductors to the Backup Gateway Supply terminals or main breaker if present.

• Connect the home load panel conductors to the Backup Gateway's Backup Terminals

• For partial home backup with Non Backup loads under 100A, a Non-Backup panel can be connected.

Optional Panelboard Kit

The internal panelboard kit may be installed in the Backup Gateway 2 and connected to either the Backup side or to the Non Backup terminals by feeding a two pole breaker on the bussing.

• • Mount the internal panelboard using the provided mounting screws.

  • Breakers in the Backup Gateway has a breaker hold down kit.  

Backup Wiring

• • The included jumpers will block the outer L1 and L2 load side lugs once installed. Be sure to land and torque all other backup conductors before installing the jumpers. It is recommended to phase tape the jumpers.

  • Note that the jumper wires cross over, which makes the first breaker space L2. This is indicated on deadfront's diagram.

• If the Gateway is the main point of disconnect (disconnect from the grid) 

  • Install Main Breaker in the supply side lugs from the approved breaker list

Non-Backup Wiring

If using the Panelboard for non-backup loads, connect the non-backup lugs to an Eaton Breaker (up to 100A) on the bussing. The kit does not include pre-made jumpers. SO the installers will need to install wires that comply with NEC 310.16

Key Points to remember

• Do not flip the Gateway 2 or it's internal components.

• Top entry requires the use of a Tesla conduit hub.

• Remove the bonding strap if the Gateway is downstream of the main service disconnect.

• Refer to the chart on the back of the deadfront for torque specs and wire gauges

• If using the panel board kit, be sure to land and torque conductors on the outer lugs before installed the feeder wires to the panel board.

• Do not run wires across the middle of the unit

• Fabricate and install the Powerwall communication connector