Samlexpower Evolution EVO-2212 Owner's Manual - page 61
60 | SAMLEX AMERICA INC.
SAMLEX AMERICA INC. | 61
4.5.1 AC Transfer and Output Neutral To Chassis Ground Bond Switching
As required by NEC and UL specification 458, AUTOMATIC Ouput Neutral to Chassis Ground
bond switching arrangement has been provided in these units through “Output Neutral to
Chassis Ground Bond Switching Relay” [K4 in Figs 4.1(a) and 4.1(b)] to switch bonding of the
Neutral Output Connector of the Inverter Charger as follows:
• When operating as an inverter, the current carrying conductor of the Inverter Section that is
connected to the Output Neutral connector of the Inverter Charger is bonded to the metal
chassis of the inverter by the “Output Neutral to Chassis Ground Bond Switching Relay”
[K4 in Figs 4.1(a) and 4.1(b)]. As the metal chassis of the inverter is in turn bonded to the
RV Ground (chassis of the RV) or to the Boat Ground (DC Negative Grounding Bus Bar and
the Main AC Grounding Bus Bar are tied together in a boat and this is called the “Boat
Ground”), this current carrying conductor of the Inverter Section will become the Grounded
Conductor (GC) or the Neutral of the Inverter Section.
• When in Charging Mode, the Neutral conductor of the Grid power/Generator will be
connected to the Output Neutral connector of the Inverter Charger. At the same time, the
“Output Neutral to Chassis Ground Bond Switching Relay” [K4 in Figs 4.1(a) and 4.1(b)] will
unbond (disconnect) the Output Neutral connector of the Inverter Charger from the chassis
of the Inverter Charger. This will ensure that the Grounded Conductor (GC) / Neutral of the
Grid power/Generator is bonded to the Earth Ground at one single point at the location of
the AC Power Distribution System of the Marina/RV Park.
• Disabling Neutral to Ground Bond: In some applications, the Output Neutral may be
required to remain isolated from the chassis/Ground at all times. For this, automatic Output
Neutral to Ground bond can be disabled by disconnecting the Male/Female Quick Discon-
nect located in the AC wiring compartment. [Please see (i) 13, Fig 3.9 and (ii) "QD' in Figs
4.1(a) and 4.1(b)]
Please read the following on-line White Papers for more details at www.samlexameri-
ca.com (Home > Support > White Papers):
- “Grounded Electrical AC Power Distribution”
- “Grounding System and Lightning / Ground Fault Protection”
- “Neutral to Ground Switching in RV and Marine Applications”
4.5.2 Operation of Transfer and Output Neutral and Chassis Ground Bond
Switching Relays – EVO-2212 and EVO-2224
Refer to Schematic at Fig 4.1(a)
The Bi-directional Transformer is used as follows:
o Feeds AC output from the Inverter Section when Grid / Generator power is not available.
o Feeds Grid / Generator power to the Battery Charger Section when Grid / Utility are
available.
Switching of Hot Output (OUTPUT LINE)
o 40A rated SPDT Relays K2 and K3 are used to switch the Hot Output Connector (OUT-
PUT LINE) to either the Inverter Section or to the Grid / Generator
o When Grid / Generator Power is available, relays K2 or K3 will be energized and con-
tact 4 switches over to contact 5 (Grid has PRIORITY over Generator if both are present
SECTION 4 |
General Description & Principles of Operations