ISSPRO R4023-24VDC - Manual (Page 5)

Form No. IS051 - (10/31/00 Rev. B) Page 5 of 5
VERY IMPORTANT!!!
Low Water Level Probe Installation:
1. TO TANK RADIATORS: Locate a point on the side of the tank away from the hose connections, but near the center
of the tank, and ¾” above the core. (Fig. 1A) (The probe may also be mounted at the centered top of the tank,
providing the bottom of the probe reaches sufficiently into the water. Be sure that the probe does not touch the top of
the core, when fully inserted.) (See Fig. 1B)
2. SIDE TANK RADIATORS: Locate a point on the side tank to give adequate warning. (See Fig. 2)
3. For aluminum and stainless steel tanks with a wall thickness of 1/8” or greater, drill a 7/16” hole at selected point and
tap for ¼” N.P.T. (For thin wall brass radiators drill a 5/8” hole and silver solder the supplied brass bushing.)
4. Apply silicone sealant to the probe threads and screw the probe firmly into the tapped hole.
5. If the water level warning is not going to be used with the shutdown, then it is necessary to jumper the water level
probe input to the negative (“-“) terminal. (** See wiring diagram.) Failure to follow this procedure will cause the
shutdown to work improperly. This system will not work correctly if the radiator is not grounded or if the radiator
has plastic tanks. Please consult ISSPRO for assistance.
6. When wiring the probe to the control box you may also install an optional test switch as shown in the diagram.
PLEASE NOTE!!!
(Excerpt from page number 2)
Form No. IS051 - (10/31/00 Rev. B)