Summary of the content on the page No. 1
L4188A,B; L4189A,B; L6188A-C;
®
L6189A-C Aquastat Controllers
PRODUCT DATA
FEATURES
L4188 and L4189 provide spst switching for high and
low limit control.
L6188 and L6189 provide spst switching for low limit
and circulator control.
L4188, L6188 models are direct-mounted.
L4189, L6189 models are remote bulb.
Diaphragm-operated switch breaks on temperature
rise (spst and normally closed spdt contacts).
Compact controller case for application flexibility.
Remote Bulb with
Screwdriver
Summary of the content on the page No. 2
L4188A,B; L4189A,B; L6188A-C; L6189A-C AQUASTAT® CONTROLLERS SPECIFICATIONS Electrical Ratings: Terminals: 1/4 in. male quick-connects standards. Options (specify when ordering): 24 Vac 120 Vac 240 Vac Combination screw and 1/4 in. quick connects. Full Load 2.0 A 8.0 A 5.1 A Separate grounding terminal. Locked Rotor 48.0 A 30.6 A Temperature Setting Range: 80° to 200° F (27° to 93° C), 110° to 230° F (43° to 110° C), and 160° to 280° F (71° to Switching: Diaphragm-operated, snap-acting switch
Summary of the content on the page No. 3
L4188A,B; L4189A,B; L6188A-C; L6189A-C AQUASTAT® CONTROLLERS Ambient Temperature Range: 32° to 158° F (0° to 70° C). Dimensions: See Fig. 1. Mounting: Must be mounted in an enclosure that meets local Sensing Bulb: Liquid-filled copper (See Fig. 1). electrical codes. Direct: Unit mounts on immersion well at desired sensing Underwriters Laboratories Inc. Component Recognized: location. File No. MP466, Guide No. MBPR. Remote bulb: Sensing bulb is inserted into immersion well at desired sensing lo
Summary of the content on the page No. 4
L4188A,B; L4189A,B; L6188A-C; L6189A-C AQUASTAT® CONTROLLERS Accessories (order separately): 3. Refill the system. Check for and correct any leaks. Capillary compression fittings. USE MODERATE AMOUNT Part No. 104484A: 1/2 in. NPT spud. OF PIPE COMPOUND Part No. 104484B: 3/4 in. NPT spud. Immersion well: Pressure rating 255 psi [1760 kPa]. Part No. 45900409-003B: 1/2 in. BSPT spud, 1 in. insulation, 3-1/2 in. insertion. Part No. 45900409-009B: 1/2 in. NPT spud, 1-1/2 in. LEAVE 2 END THREADS BAR
Summary of the content on the page No. 5
L4188A,B; L4189A,B; L6188A-C; L6189A-C AQUASTAT® CONTROLLERS 4. ADJUSTABLE DIFFERENTIAL MODELS ONLY: Set Mounting Behind Panel-Controller with Knob differential. See Adjustment and Checkout section. 5. Using setting indicator as a template, mark and drill NOTE: The panel can be up to 5/64 in. thick. holes in the panel for the mounting screws and for the knob shaft. 1. Uncoil capillary, starting at bulb. Avoid sharp bends or 6. Mount the controller behind, and the setting indicator in kinks
Summary of the content on the page No. 6
L4188A,B; L4189A,B; L6188A-C; L6189A-C AQUASTAT® CONTROLLERS MOUNTING TEMPLATE NO. 10 3/4 SHEETMETAL 3/16 5/16 3/16 SCREWS (2) 1 (OBTAIN LOCALLY) 1 PANEL 2 MOUNTING 5/8 BRACKET 3/16 3 1 DRILL 2 MOUNTING SCREW HOLES. 2 DRILL HOLE FOR SLOTTED SHAFT. USE SMALL HOLE FOR SHAFT ONLY; LARGE HOLE SHAFT PLUS SETTING SCALE. 3 DRILL SMALL HOLE FOR MODEL WITH MANUAL RESET BUTTON OR LARGE HOLE FOR MODEL WITH DIFFERENTIAL ADJUSTMENT. CONTROLLER CAPILLARY CONTROLLER M25420 SLOTTED SHAFT Fig. 7. The Controller
Summary of the content on the page No. 7
L4188A,B; L4189A,B; L6188A-C; L6189A-C AQUASTAT® CONTROLLERS OPERATION 24V THERMOSTAT As the liquid filing the sensing bulb and capillary expands and contracts, it moves a diaphragm. Movement of the diaphragm is transferred by a lever to the snap-acting switch in the RELAY CENTER controller. RG L1 (HOT) High or Low Limit Action (L4188, L4189) PROTECTORELAY L2 CONTROL The normally closed C-1 contacts open on temperature rise to 2 HIGH LIMIT the set point, shutting off power to the controlled
Summary of the content on the page No. 8
L4188A,B; L4189A,B; L6188A-C; L6189A-C AQUASTAT® CONTROLLERS To Set Adjustable Differential (if provided) Use a screwdriver to turn the differential dial until the slot AJUST LIMIT STOP molded into the case lines up with the desired degrees of differential. LIFT AND PUSH TO CHANGE LIMIT CONTROLLER SETTING LIMIT STOP POINTER KNOB DIFFERENTIAL ADJUSTMENT DIAL REPLACE KNOB ON SHAFT SETTING INDICATOR M25425 SETTING INDICATOR: LIMIT STOP MUST BE ON RIGHT SIDE OF Fig. 12. Twist the Screwdriver Slight
