4 alarms and relays – Hach-Lange SC 60 User Manual
Page 22
18
Installation
3.4 Alarms and Relays
DANGER
Explosion hazard. Do not connect or disconnect electrical
components or circuits to the equipment unless power
has been switched off or the area is known to be
non-hazardous.
DANGER
Exposure to some chemicals may degrade the sealing
properties of materials used in the following devices: Relays
K1, K2, and K3. Periodic inspection of these devices is
recommended to check for degradation.
The controller is equipped with three unpowered relays rated
100–230 VAC, 50/60 Hz, 5 amp resistive maximum. See the sensor
manual for relay setup details.
3.4.1 Connecting the Relays
DANGER
Relay loads must be resistive. User must externally limit
current to the relays to 5 Amps by use of a fuse or a breaker.
DANGER
Power and relay terminals are designed for only single wire
termination. Do not use more than one wire in each terminal.
The relay connector accepts 18–12 AWG wire (as determined by
load application). Wire gauge less than 18 AWG is not advised.
The Normally Open (NO) and Common (COM) relay contacts will
be connected when an alarm or other condition is active. The
Normally Closed (NC) and COM relay contacts will be connected
when an alarm or other condition is inactive or when power is
removed from the controller.
AC Line (100–230 V) Powered sc60s
AC line powered sc60 controllers contain three relays designed for
connection to AC MAINS circuits (voltages greater than 30V-RMS,
42.2V-PEAK or 60 V DC). Refer to
Figure 15 on page 19
for
connection information. The relay wiring compartment is not
designed for voltage connections below these levels. Relays must
not be powered from the same wiring used to power the controller.
24 VDC Powered sc60
The 24 VDC sc60 controller contains three relays designed for
connection to LOW voltage circuits (i.e., voltages less than
30V-RMS, 42.2V-PEAK or 60 V DC). Refer to
Figure 15 on page 19
for connection information. The wiring section is not designed for
voltage connections above these levels. Relay must not be
powered from the same wiring used to power the controller.