Kohler KEP User Manual

TP-6745 7/10 51Section 3 Controller Test and Replacement
3.5 Operation Diagrams
This section contains descriptions and diagrams of the
power switching device operation. For complete
diagrams, refer to the schematic diagrams provided with
the transfer switch.
The ATS controller monitors the connected source and
detects source failure, either a complete loss of the
source or a source parameter that is outside the
acceptable range. The controller starts the engine start
time delay. If power is restored before the time delay
ends, the controller resets the time delay and continues
to monitor the source. If the source failure persists and
the time delay ends, the controller closes the engine
start contacts to signal the Source E generator set to
start.
When Source 2 (or the standby source) becomes
available, the controller starts the preferred-to-standby
time delay (if not set to zero). When the time delay ends,
relay K2 in the controller closes, applying power to the
circuit breaker motor operator to open the Source 1
circuit breaker.
Note: Controller relays K1 and K2 and programmed
transition interface board (PTIB) relays K1’ and
K2’ are energized for only 250 milliseconds to
initiate transfer.
Service entrance models stop in the OFF position for a
programmed length of time during transfer. On MCCB
models, the K2 relay closes after the Off time delay,
applying power to the circuit breaker motor operator and
closing the Source 2 circuit breaker. On ICCB models,
the transfer-to-OFF sequence is controlled by the K1’
and K2’ relays on the programmed-transition interface
board (PTIB).
The motor operator power circuits vary for MCCB and
ICCB models. The following sections illustrate the
transfer sequence for the different models.
When Source N (or the preferred source) is restored, the
controller starts the standby-to-preferred time delay.
When the time delay ends, the controller’s K1 (NR) relay
closes, applying power to the circuit breaker motor
operator and initiating transfer back to Source N (or the
preferred source).
The controller K1 and K2 relays and the PTIB relays are
replaceable.
Note: Always check all wiring and connections before
replacing parts.
Figure 3-7 explains the notation used in the solenoid
operation diagrams in Figure 3-8 through Figure 3-11.
Legend:
K1, K2 Controller relays. Energized for 250 milliseconds to initiate transfer.
K1’, K2’ Programmed-transition interface board (PTIB) relays Energized for 250 milliseconds to initiate transfer.
M Circuit breaker motor operator, MCCB models
UBC Utility Breaker Close Motor Operator, ICCB Models
UBO Utility Breaker Open Motor Operator, ICCB Models
GBC Generator Breaker Close Motor Operator, ICCB Models
GBO Generator Breaker Open Motor Operator, ICCB Models
Power through the coil circuit.
Figure 3-7 Legend for Solenoid Operation Diagrams

Kohler KEP Specifications

General

Brand	Kohler
Model	KEP
Category	Switch
Language	English