Remote Alarm Contacts; Communications; G And H Panel Generators; Non G And H Panel Generators - Generac Power Systems HTS Owner's Manual

General Information
When the power is first applied, the unit does a brief
internal diagnostic test. During this test, the red LED will
illuminate briefly, go off and then the green LED will illu-
minate.
For the power source to be available, the associated ser-
vice disconnect circuit breaker must be ON, the associ-
ated TVSS disconnect circuit breaker must be ON and
the associated source must be present.
The LED status indicators can be viewed directly on the
TVSS module with the enclosure door open.
2.1.2.6—Remote Alarm Contacts
Each TVSS module is equipped with a set of alarm con-
tacts to indicate the TVSS module protection status, to a
external alarm. This is available as a full set of dry relay
contacts (C, NO, NC). The contact ratings are: 3A,
120Vac maximum. The contacts are wired to a three
position terminal strip for customer connection.
If the contacts change state, it indicates either a power
failure to the TVSS module or a failure of the TVSS mod-
ule.
2.2 — Communications
2.2.1— G and H Panel Generators
The HTS acts as a Modbus slave on the communications
network. For the "H" series of generator controllers, Port
1 is used for the connection. On the "G" series of control-
lers, Port 0 is used. The base Modbus address for the
transfer switch is set at 240 but can be modified using dip
switches DIP1 - switches 7 and 8. Unless there are two
transfer switches on the network, these switches can be
left OFF.
Communications parameters on the Power Manager
should be set to:
• Modbus Master Port
• 4800 Baud
•
No parity, 2 stop bits
The Network uses Modbus RTU protocol. Communica-
tions are sent at a one second rate. If no Good messages
are received within 20 seconds, the communications link
is determined to be bad and the switch controller will
revert to local control. If the link re-establishes itself the
remote control from the H-panel restarts. See Figure 2-1.
4
Figure 2-1. Typical Communication Network
2.2.2— Non G and H Panel Generators
This switch is provided with a "2-wire start" output. The 2-
wire start output is for use with non-G and H control panel
generators. The 2-wire start connection is made on the 6
position terminal strip labeled Engine Generator Connec-
tions, wire numbers 178 and 183. This connection is best
used as a back up to the normal RS-485 communication
link.
The 2-wire start output allows the ATS to start and stop
the generator automatically. Without a RS-485 communi-
cation link and 2-wire start, the timing functions of the
transfer switch will be the last settings downloaded from
the G or H panel or if all power is removed from the ATS,
the controller will revert to the default settings.
2.3 — Operation With Loss of Com-
munications
Local control means that if the generator is running, the
generator can be running in Manual or Auto. If there is no
utility, the switch will transfer to the generator. If utility
returns, the switch will transfer back to utility. If only the
RS-485 communication lines are connected, the genera-
tor will not start or stop automatically as it cannot commu-
nicate with the switch to know the utility is missing. It will
have to be manually started and stopped (with the key-
switch set in the manual position). If the RS-485 commu-
nication link is not functioning and the 2-wire start lines
are connected between the HTS and the generator, the
generator will start and stop automatically via the 2-wire
start lines.
Automatic Transfer Switch Owner's Manual