Hardware Interlock Jumpers - Link4 iGrow 1800 Installation And User Manual

Hardware Interlock Jumpers

Hardware Interlock is a protective mechanical mechanism that prevents two adjacent outputs (1&2, 3&4,
etc.) from coming on at the same time. It is useful for such equipments such as reversible motors and
two speed motors, where it is vital that only one output be turned on at a time

The iGrow 1800 is shipped with all the hardware interlocks disabled. Removing both jumpers for each
curtain, vent or two speed fans enables interlock jumpers. It is important to remove the paired set of red
jumpers with these types of equipment to prevent the possibility of a short in the event the open and close
switches are turned on at the same time. Usually, the contractors in the relay panel have mechanical
interlocks to prevent this from happening and the iGrow interlocks act as a backup. Simply remove the
paired set of red terminal jumpers that are associated with each channel wired as an interlock contact.
See Figure 4.11and Figure 4.12 to view an example of "wet" and "dry" interlocked diagrams.
Note: When a paired set of red interlock terminal jumpers is removed, the corresponding front panel
switches will affect the manual override switches. Manual toggle switches can be used to override,
unless the motor or device is already active or in motion. If you want to manually override a vent,
curtain or two speed fan, put both switches in the Off position prior to switching On one of the
switches.
iGrow 1800 Installation Guide Page21 Link4 (714) 524-0004