Home Standby; Prepackaged; Generators - Guardian 4721 Repair Manual

SECTION 1.2
PREPACKAGED INSTALLATION BASICS
THE TRANSFER SWITCH
A transfer switch is required by electrical code, to pre-
vent electrical feedback between the utility and stand-
by power sources, and to transfer electrical loads
from one power supply to another safely.
PREPACKAGED TRANSFER SWITCHES:
Instructions and information on prepackaged transfer
switches may be found in Part 3 of this manual.
POWER SOURCE AND LOAD LINES
The utility power supply lines, the standby (generator)
supply lines, and electrical load lines must all be con-
nected to the proper terminal lugs in the transfer
switch. The following rules apply:
In 1-phase systems with a 2-pole transfer switch, con-
nect the two "Utility" source hot lines to transfer
switch Terminal Lugs N1 and N2. Connect the
"Standby" source hot lines (E1, E2) to transfer switch
Terminal Lugs E1 and E2. Connect the load lines
from transfer switch Terminal Lugs T1/T2 to the elec-
trical load circuit. Connect "Utility", "Standby" and
"Load" neutral lines to the neutral block in the transfer
switch.
SYSTEM CONTROL INTERCONNECTIONS
Prepackaged home standby generators are equipped
with a terminal board identified with the following ter-
TRANSFER
SWITCH
REMOTE TEST
SWITCH (OPTIONAL)
- OPEN SWITCH TO TEST -
SWITCH TYPE, SPST
ELECTRICAL RATINGS,
2A @ 250Vac MIN.
Page 8
UTILITY SUPPLY WITH
SERVICE DISCONNECT
NEUTRAL
LUG
N1 N2
E1 E2
T1 T2
CUSTOMER
LOAD
Figure 4. Prepackaged Interconnection Diagram
PART 1
minals: (a) utility 1, (b) utility 2, (c) load 1, (d) load 2,
(e) 23, and (f) 194. Prepackaged transfer switches
house an identically marked terminal board. Suitable,
approved wiring must be interconnected between
identically numbered terminals in the generator and
transfer switch. When these six terminals are properly
interconnected, dropout of utility source voltage below
a preset value will result in automatic generator start-
up and transfer of electrical loads to the "Standby"
source. On restoration of utility source voltage above a
preset value will result in retransfer back to that source
and generator shutdown. System control wiring must
be routed through its own separate conduit.
A control board, mounted on the standby generator
set, provides a "7-day exercise" feature. This feature
allows the standby generator to start and run once
every 7 days, on a day and at a time of day selected.
The timer clock that controls this automatic exercise
of the unit must be powered by voltage from the
transfer switch Load 1/Load 2 terminals. If the exer-
cise function is to be made available, connect suitable
wiring from the ATS transfer switch load terminal lugs,
to the "Load 1/Load 2" terminals in the generator.
The control board in the generator also provides a
battery "trickle charge" circuit. This circuit, when pow-
ered by utility source voltage, will deliver a charging
voltage to the battery during non-operating periods to
keep the battery charged. To use the trickle charge
feature, connect suitable wiring to the generator's
"Utility 1/Utility 2" terminals and to the appropriate ter-
minals in the "ATS" transfer switch.
NOTE:
POWER LEADS AND
TRANSFER SWITCH
LEADS MUST BE
RUN IN TWO
DIFFERENT CONDUITS.
GENERAL INFORMATION
22
33
NEUTRAL
CONNECTION
11
CB1
44
UTILITY 1 (N1)
UTILITY 2 (N2)
LOAD 1 (T1)
LOAD 2 (T2)
23
194
AC GENERATOR
CONTROL PANEL