resideo L8151A Triple Function Aquastat Relay Installation Guide
- June 6, 2024
- resideo
Table of Contents
resideo L8151A Triple Function Aquastat Relay
APPLICATION
The L8151A is a remote bulb controller for use with hydronic heating systems
that include domestic hot water service.
FEATURES
- Provides high limit, low limit, and circulator control for maintaining boiler temperatures.
- Can provide multizone control by using a separate thermostat and R845 Relay for each zone.
- An internal transformer powers the thermostat circuit.
- Shielded capillary allows convenient mounting.
- Consists of a diaphragm powerhead and micro switch assembly that responds to temperature changes in the boiler water.
SPECIFICATION
IMPORTANT
The specifications given in this publication do not include normal
manufacturing tolerances. Therefore, this unit may not exactly match the
listed specifications. Also, this product is tested and calibrated under
closely controlled conditions, and some minor differences in performance can
be expected if those conditions are changed.
MODEL:
L8151A Triple Aquastat® Relay for remote bulb control of hydronic heating
systems that include domestic hot water.
Electrical Ratings:
Power Supply: 120 Vac, 60 Hz; 220 Vac, 50 Hz and 240 Vac, 60 Hz operation.
Contact Ratings (A): See Table 1.
| 120 Vac | 240 Vac | |
|---|---|---|
| Full Load | 7.4 | 3.7 |
| Locked Rotor | 44.4 | 22.2 |
MAXIMUM POWER CONSUMPTION:
8W at 120 Vac, 60 Hz.
MAXIMUM AMBIENT TEMPERATURE:
150°F (66°C) at case. 265°F (130°C) at sensing element.
PRESSURE RATING:
200 psi (1380 kPa) on outside of immersion well.
THERMOSTAT HEAT ANTICIPATOR SETTING:
0.2A.
LOW LIMIT (Fig. 2):
Function: Maintains water temperature at setting during thermostat off
periods.
Setting: 110°F to 220°F adjustable (43°C to 104°C).
Differential: 10°F to 25°F adjustable (6°C to 14°C).
HIGH LIMIT (Fig. 2):
Function: Opens burner circuit if water temperature reaches high limit
setting.
Setting: 130°F to 240°F adjustable (54°C to 116°C).
Differential: 10°F fixed (6°C).
MOUNTING MEANS:
Mounting lugs on back of case.
DIMENSIONS :
See Fig. 1.
SENSING ELEMENT :
3/8 x 2-7/8 in. (10 x 73 mm).
CAPILLARY LENGTH:
36 in. (914 mm), armored capillary.
UNDERWRITERS LABORATORIES INC. LISTED:
File No. MP466, Guide No. MBPR2.
INSTALLATION
When Installing This Product…
- Read these instructions carefully. Failure to follow them could damage the product or cause a hazardous condition.
- Check the ratings given in the instructions and on the product to make sure the product is suitable for your application.
- Installer must be a trained, experienced service technician.
- After installation is complete, check out product operation as provided in these instructions.
WARNING: Can cause property damage, severe injury or death. Product is
for use only in a system with a pressure relief valve.
CAUTION
- Disconnect power supply before beginning installation to prevent electrical shock or equipment damage.
- Avoid making sharp bends or kinks in the capillary. Bends should be no less than 1 in. (25 mm).
IMPORTANT: Terminals on these Aquastat® Relays are approved for copper
wire only.
Mounting the Case
Mount the case in a convenient location near the boiler. Remember that the shielded capillary must reach from the case to the immersion well. This maximum ambient temperature of the selected location must not exceed 150°F (66°C) at the case, 265°F (130°C) at the sensing element.
Immersion Well Mounting
NOTE : Immersion well must be ordered separately. For a list of available wells, refer to form 68-0040, Wells and Fittings for Temperature Controllers.
The boiler manufacturer generally provides a tapping for the immersion well.
This tapping should be located at a point where typical water temperature can
be measured. The
immersion well must never be located close to a hot or cold water inlet or a
steam coil, or where the pressure exceeds 200 psi (1380 kPa). If the system is
filled, drain to a point below the selected installation location.
- Screw the well into the boiler, tank, or pipe tapping.
- Insert the bulb into the well, pushing tubing until bulb bottoms in well. Avoid making sharp bends or kinks in the capillary. Bends should be no sharper than 1 in. (25 mm) radius.
- Attach the retainer clamp to end of well spud. Loosen draw nut and spread jaws of clamp with screwdriver if necessary, Fig. 3.
- With part no.121371AA Retainer Clamp attached to well spud (be sure jaws of clamp hook over ridge at end of spud, as shown at points A), adjust tubing to fit through retainer clamp groove, as shown at point B.
- Tighten draw nut so that retainer clamp is firmly attached to well spud and tubing is held securely in place. Be careful not to damage the capillary.
- Carefully coil the excess capillary at the bottom of the Aquastat® case.
Wiring
CAUTION
- Disconnect power supply before wiring to avoid electrical shock or equipment damage.
- Be sure the terminal connections are inside an enclosure that meets local codes.
IMPORTANT
Terminals on the L8151A Aquastat® Relay are approved for use only with copper
wire. The terminals allow wraparound wiring only.
- Strip 7/16 in. of insulation from the wire end.
- Wrap the wire at least three fourths of the distance around the screws as shown.
- Use a standard flat-headed screwdriver to tighten the screw until the wire is snugly in contact with the screw and contact plate.
- Tighten the screw an additional one-half turn.
NOTE : Do not use a push-type ratchet screwdriver.
All wiring must comply with local electrical codes and ordinances. The limits
given in the Specifications section must not be exceeded when applying this
control. Use manufacturer instructions when wiring controlled equipment or
refer to typical hookups in Fig. 4 through Fig. 6. When the B1 terminal on the
device being replaced is 1/4 in. tab terminal, use the existing wiring harness
terminals to install the replacement device. When the B1 terminal on the
device being replaced is a screw terminal, insert the provided tab terminal to
screw terminal adapter on the 1/4 in. tab terminal of the replacement device.
After the adapter is installed, the existing wraparound wire end can be reused
to make an electrical connection to the B1 terminal.
NOTE : Do not use a push type ratchet screwdriver.
- Strip 7/16 in. of insulation from the wire end.
- Wrap the wire at least three-fourths of the distance around the screw as shown.
- Using a standard, flat-headed screwdriver, tighten the screw until the wire is snugly in contact with the screw and contact plate.
- Tighten the screw an additional one-half turn.
L8151A TRIPLE AQUASTAT® RELAY
High Limit
The high limit opens and turns off the burner when the water temperature reaches the setpoint. The high limit automatically resets after the water temperature drops past the setpoint and through the 10°F (6°C) differential.
WARNING: Can cause property damage, severe injury or death. Product is for use only in a system with a pressure relief valve.
Low Limit and Circular Control
On a temperature rise, with the adjustable differential at the minimum setting
of 10°F (6°C), the low limit circuit (RB) breaks and the circulator circuit
(R-W) makes at the control setpoint. On a temperature drop of 10°F (6°C) below
the setpoint, the R-B circuit makes and the R-W circuit breaks.
- POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
- CONTROL CASE MUST BE CONNECTED TO EARTH GROUND. USE GROUNDING SCREW PROVIDED.
- LINE VOLTAGE OIL BURNER CONTROL OR GAS VALVE.
- B1 IS 1/4 IN. TAB TERMINAL.
At any differential setting greater than 10°F (6°C), the R-B make and R-W break temperatures remain the same (control setting minus 10°F (6°C). The R-B break and R-W make temperatures are the setpoint temperatures plus the difference between the differential setting and 10°F (6°C).
EXAMPLE : Setpoint of 140°F (60°C) differential set at 25°F (14°C). On a temperature rise, R-B breaks and R-W makes at 155°F (68°C). On a temperature fall, R-B makes and R-W breaks at 130°F (54°C); see Fig. 7.
Thermostat Anticipator
Set the thermostat heat anticipator at 0.2A.
CHECKOUT
Put the system into operation and observe each function through at least one
complete cycle. Be sure the control operates as intended.
Resideo Technologies, Inc.
1985 Douglas Drive North, Golden Valley, MN 55422
1-800-468-1502
60-2553—04 M.S. Rev. 07-20 | Printed in United States
© 2020 Resideo Technologies, Inc. All rights reserved. This product is
manufactured by Resideo Technologies, Inc. and its affiliates.
References
Read User Manual Online (PDF format)
Read User Manual Online (PDF format) >>