Brochure

63-8702 55
Aquastat
®
Controllers
L4081; L6081 Multiple Aquastat
®
Controllers
High limit, low limit and/or circulator controllers used to regulate
boiler water temperature in gas- or oil-fired hydronic heating systems.
• An immersion type liquid-filled sensing element actuates two snap
switches.
• One switch operates as a high limit control.
• The other switch operates as a low limit and/or circulator control,
depending on the model.
• Controller may be mounted in any positioning and needs no
leveling.
• Separate, easy-to-read, calibrated dial and setpoint adjustments for
each switch.
• Differential adjustment on low limit or circulator switch on select
models.
• All adjustments accessible inside front cover.
• Push-in terminals for quick connecting.
• Single sensing element for easy installation.
• Two SPST snap switches act independently at respective
temperature settings.
Dimensions in inches (millimeters)
7/8 IN. (22 MM) DIA. KNOCKOUT
FOR 1/2 IN. (12.5) CONDUIT (6)
1-3/16
(30)
2-3/64 (63)
4-3/32 (125.5)
3/4
(19)
(2)
(2)
1-13/64
(30.5)
(2)
1-13/64
(30.5)
WELL-CLAMP
SCREW
MAXIMUM INSERTION 3-1/2
(89)
INSULATION DEPTH, 1-1/2 (38)
OR 3 (76)
1-3/8
(35)
(2)
1-13/16
(46)
(4)
2-11/16 (68)
3/4-14 NPT OR 1/2-14 NPT
3-7/8
(98.5)
M8854
Temperature Range: Maximum – 150°F (66°C) at switches; 265°F
(129°C) at sensing element
Operating Temperature Range:
High Limit – 130°F to 240°F (54°C to 116°C);
Low Limit –110°F to 220°F (43°C to 104°C)
Electrical Ratings: 0.25 A @ 0.25 to 12 Vdc;
At Full Load – 8A @ 120 Vac: 5.1A @ 240 Vac;
At Locked Rotor – 48A @ 120 Vac: 30.6A @ 240 Vac
Electrical Ratings, Ignition: Transformer Load: 360 VA
Mounting: Horizontal
Dimensions: 3 7/8 in. high x 4 1/8 in. wide x 2 3/4 in. deep. (98 mm
high x 105 mm wide x 70 mm deep.)
Operating Humidity Range (% RH): 0 to 95% RH, non-condensing
Approvals, Underwriters Laboratories Inc.: UL Listed: File No. MP466,
Vol. 12, Sec. 4, Guide No. MBPR2
Approvals, CSA: Certified: File No. LR95329-1
Material Number Application Differential Temperature Well Spud Size Insulation Depth Switching Action
L4081A1023/U High and Low limit High limit : 10°F fixed;
low limit: 10-25°F adj.
3/4 in. - 14 NPT (19 mm - 14 NPT) 1 1/2 in. (38 mm) SPST: High & Low Limit
L4081B1047/U High Limit and Circulator High limit : 10°F fixed;
low limit: 10-25°F adj.
3/4 in. - 14 NPT (19 mm - 14 NPT) 1 1/2 in. (38 mm) SPST: High Limit &
Circulator
L4081B1096/U High Limit and Circulator 10°F Fixed – 3 in. (76 mm) SPST: High Limit &
Circulator
L6081A1036/U High and Low Limit and
Circulator
High limit : 10°F fixed;
low limit: 10-25°F adj.
3/4 in. - 14 NPT (19 mm - 14 NPT) 1 1/2 in. to 4 in. (38 mm) SPST: High Limit
SPDT: Low Limit and
Circulator