Hach SC1500 Manuel D'utilisation page 16

Potential Electrocution Hazard. Power and relay terminals are designed for only single
wire termination. Do not use more than one wire in each terminal.
Potential fire hazard. Do not daisy-chain the common relay connections or jumper wire
from the mains power connection inside the instrument.
Fire hazard. Relay loads must be resistive. Always limit current to the relays with an
external fuse or breaker. Obey the relay ratings in the Specifications section.
If the instrument has the optional relay card, the instrument has four non-powered, double-pole
relays. Each relay changes state when the selected trigger condition for the relay occurs.
The relay terminals are located behind a high-voltage barrier in the controller enclosure. Do not
remove the barrier while power is supplied to the relay terminals. Do not supply power to the relay
terminals when the barrier is not installed.
Connect each relay to a control device or an alarm device as necessary. Refer to the illustrated steps
that follow and Table 4
condition for each relay.
Refer to Specifications
and the low-voltage input/output circuitry.
The relay terminals accept 15 AWG wire (as determined by load application). Use wire with an
insulation rating of 300 VAC or higher. Wire gauge other than 15 AWG is not recommended.
The current to the relay contacts must be 5 A or less. Make sure to have a second switch available to
remove power from the relays locally in case of an emergency or for maintenance.
When switching large inductive loads (e.g., motors and pumps) or currents higher than 5 A, use an
auxiliary relay to extend the relay life.
Use the relays at either all high voltage (greater than 30 V-RMS and 42.2 V-PEAK or 60 VDC) or all
low voltage (less than 30 V-RMS and 42.2 V-PEAK, or less than 60 VDC). Do not configure a
combination of both high and low voltage.
Relay terminal connections to the mains circuit in permanent connection applications must have
insulation rated for a minimum of 300 V, 70 °C (158 °F). Terminals connected to the mains circuit
with a power cord connection must be double insulated and rated 300 V, 70 °C (158 °F) at both the
inner and outer insulation levels.
16 English
W A R N I N G
W A R N I N G
C A U T I O N
to connect the relays. Use the mobile application to select the trigger
on page 3 for the relay specifications. The relays are isolated from each other