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Mascot II Boilers and Water Heaters

Page 25

SECTION 7.
Electrical Connections

WARNING

The appliance must be electrically grounded in
accordance with the requirements of the authority
having jurisdiction or, in the absence of such
requirements, with the latest edition of the National
Electrical Code, ANSI/NFPA 70, in the U.S. and with
latest edition of CSA C22.1 Canadian Electrical Code,
Part 1, in Canada. Do not rely on the gas or water piping
to ground the metal parts of the boiler. Plastic pipe or
dielectric unions may isolate the boiler electrically.
Service and maintenance personnel, who work on or
around the boiler, may be standing on wet floors and
could be electrocuted by an ungrounded boiler.
Electrocution can result in severe injury or death.

Single pole switches, including those of safety

controls and protective devices must not be wired in a
grounded line.

All electrical connections are made on the terminal

blocks that are located inside the control panel.

NOTE:

 All internal electrical components have been

prewired. No attempt should be made to connect
electrical wires to any other location except the terminal
blocks.

Wiring connections are shown in 

Figures 21-22.

Important Note: 

DO NOT MAKE/BREAK MASCOT II

LINE VOLTAGE TO SIGNAL CALL FOR HEAT. A “call
for heat / end call for heat” MUST be connected to the
field interlock terminals. Some Mascot II components
are designed to have constant voltage during normal
operation. If the Mascot II's supply voltage is toggled as
a call for heat signal, premature failure of these
components may result.

If using remote 4-20mA control, Mascot II does not
recognize 4mA as a signal to shut off. If the call for heat
is not connected between the field interlock terminals,
Mascot II will remain in low fire when it sees 4mA as a
modulating signal.

Caution

Mascot II supply voltage must not be disengaged,
except for service or isolation, or unless otherwise
instructed by procedures outlined in this manual. To
signal a call for heat, use the 24V field-interlock, as
shown in the wiring diagram(s).

7.1 Main Power

Plug power cord into a non-switched 115V

electrical outlet with 15A circuit protection. FLA is 2A.
There is an internal 10A breaker to protect internal
system components.

7.2 Pump Connections

Mascot II energizes the integral boiler pump (and

three-way valve if central heat) upon a call for heat.
Once the call for heat is satisfied the pump will remain
on for the defined pump overrun time.

NOTE:

 System pump contacts are dry contacts.

Appropriate voltage must be supplied to the System
pump for proper operation.

System pump connections are located in the

control panel (

see Figure 20

). The system pump

contacts are rated for 120Vac, 7.4 amps. To use the
contacts, power must be supplied on one terminal with
the other terminal wired to the pump or a relay
controlling the pump.

7.3 24Vac Transformer with Circuit Breaker

24Vac is supplied by a transformer mounted

behind the upper door. All 24Vac power is supplied
through a 2A circuit breaker located behind middle door.

7.4 Central Heat - Call for Heat

Connect the Call for Heat to terminals #1 and #2

(connections labeled "T-T or interlock").

7.5 Outdoor Air Temperature Sensor

Connect the outdoor air temperature sensor to

connections labeled "Outdoor temp sensor." The outdoor
air temperature sensor is used for warm weather shutdown
and outdoor reset.

7.6 Domestic Hot Water Connection

For LMH and indirect water heater, connect

aquastat for remote sensor to terminals 7 & 8 (see

Figures 20 and 22

).

7.7 System Sensor

(lead lag/cascading operation only)

Connect the system sensor to connections labeled

"system sensor."

7.8 External Control Connections

Connect 4-20mA signals from external controls or

building automation systems. When making the
connections, follow the polarity designations shown on
the label.

7.9 Lead Lag / Cascading Wiring

Connections

Connect each boiler in the cascade system together

by daisy chaining each control from Modbus port 1
(MB1) of the first boiler to the second and so on. This
can be done using 22awg or thicker shielded twisted pair
wire with drain. Two twisted pairs or three conductors
are needed.
a.

To daisy-chain the boilers connect a wire from Modbus

Summary of Contents for Mascot II

Page 1: ...monoxide gas in flue gases which could cause serious injury property damage or death Improper installation and or operation will void the warranty AVERTISSEMENT Assurez vous de bien suivres les instr...

Page 2: ...ating System Pump Capacity 17 SECTION 6 Water Connections 6 1 Central Heat System Piping 17 6 2 Cold Water Make Up 17 6 3 Freeze Protection 18 6 4 Suggested Piping Schematics 19 6 5 Recognized Chemica...

Page 3: ...Operating the Burner and Set Up 32 10 2 1 Burner Operation 32 10 2 2 Boiler Setup and Adjustment 33 10 3 Shutting Down Mascot II 33 10 4 To Restart Mascot II 33 SECTION 11 Maintenance 11 1 System Main...

Page 4: ...he PRV should be installed prior to filling the system Refer to Figures 1 and 2 for PRV locations IMPORTANT The inlet gas pressure to the appliance must not exceed 13 W C 3 2kPa All installations must...

Page 5: ...sponsible for shortages and damage to the shipment whether visible or concealed 1 5 Unpacking The Mascot II is shipped in a single crate with the following standard components packed with the applianc...

Page 6: ...LAARS Heating Systems Page 6 Figure 2 Location of Components...

Page 7: ...Water Heaters Page 7 Figure 3 Dimensional Drawing Cond Hydronic DHW 2nd Gas Hydronic DHW 2nd Outlet Return Inlet Return Supply Supply Outlet Supply 3 4 3 4 1 2 3 4 1 2 3 4 1 2 3 4 PVC copper NPT copp...

Page 8: ...ertified to ULC S636 Intake air pipe must be PVC or CPVC that complies with ANSI ASTM D1785 F441 ABS that complies with ANSI ASTM D1527 or galvanized material Installer must comply fully with manufact...

Page 9: ...ll bracket are purposely offset NOTE Mascot II models include 16 on center mounting holes on upper rear of boiler jacket These holes are not identified on the mounting template If mounting conditions...

Page 10: ...of the combustion air intake pipe Maximum linear pipe length allowed is shown in Table 2 Subtract 5 allowable linear ft 1 5m for every elbow used The connection for the intake air pipe is at the top...

Page 11: ...el or otherwise must be certified to this ULC standard Appropriate selection of vent material is very important for proper performance and safe operation of the Mascot II The flue temperature of the M...

Page 12: ...e a nuisance or hazard 3 Locate the vent terminal so that vent gases cannot be drawn into air conditioning system inlets 4 Locate the vent terminal so that vent gases cannot enter the building through...

Page 13: ...4 3 feet 91 cm J Clearance to nonmechanical air supply Direct vent only 12 30cm 80 285 36 91cm inlet to building or the combustion air inlet 399 850 Other than Direct vent 4 ft 1 2m below 36 inches 91...

Page 14: ...shall be the responsibility of the property owner to secure the services of qualified licensed professionals for installation of hard wired carbon monoxide detec tors a In the event that the side wal...

Page 15: ...um speed Do not operate a summer exhaust fan Close fireplace dampers 4 Place in operation the appliance being inspected Follow the lighting instructions Adjust thermostat so the appliance will operate...

Page 16: ...ing plate Mascot II will function properly without the use of high altitude modification at elevations up to 10 000 feet 3050 m 2 The maximum inlet gas pressure must not exceed 13 W C 3 2kPa The minim...

Page 17: ...toff valves where required by code Suggested piping diagrams are shown in Figures 12 through 19 These diagrams are meant only as a guide Components required by local codes must be properly installed M...

Page 18: ...a boiler is subjected to freezing conditions and the boiler is not able to fire and or the water is not able to circulate there is a risk of freezing in the boiler or in the pipes in the system When w...

Page 19: ...itable for use in the Mascot II Please refer to the manufacturers instructions for proper selection and application 1 Sentinel Performance Solutions Group 2 Hercules Chemical Company 3 Dow Chemical Co...

Page 20: ...3 42 38 15 33 31 28 Table 8 DHW and Pump Performance Data Caution Scalding Risk Laars recommends the use of a thermostatic mixing valve at domestic hot water outlet boiler location to reduce potential...

Page 21: ...Mascot II Boilers and Water Heaters Page 21 Figure 16 Hydronic Piping Multi boilers for large homes with long multiple baseboard zones Installer to provide DHW anti scald thermostatic mixing valve...

Page 22: ...LAARS Heating Systems Page 22 Figure 17 Hydronic Piping Multi boilers for large homes with long multiple radiant zones Installer to provide DHW anti scald thermostatic mixing valve...

Page 23: ...Mascot II Boilers and Water Heaters Page 23 Figure 18 Hydronic Piping Heating zones piped with zone pumps Installer to provide DHW anti scald thermostatic mixing valve...

Page 24: ...LAARS Heating Systems Page 24 Figure 19 Hydronic Piping Heating zones piped with zone valves Installer to provide DHW anti scald thermostatic mixing valve...

Page 25: ...he 24V field interlock as shown in the wiring diagram s 7 1 Main Power Plug power cord into a non switched 115V electrical outlet with 15A circuit protection FLA is 2A There is an internal 10A breaker...

Page 26: ...teps until all Modbus port 1 terminal A connections are wired d Repeat the above steps for Modbus port 1 terminal B and C connections to complete the wiring e Connect the drain wire from the twisted p...

Page 27: ...Mascot II Boilers and Water Heaters Page 27 Figure 22 Wiring Diagram...

Page 28: ...in Tables 9 11 Once in a particular menu structure navigation consists of pressing the next button to scroll from item to item and then pressing the up and down arrows to change values Once the value...

Page 29: ...to control temperature of an indirect tank 8 8 Lead Lag Cascading Lead Lag Cascading allows multiple boilers to be connected together and controlled from one common sensor input Up to 8 boilers can b...

Page 30: ...Reset Outdoor reset varies the control point setpoint based on the actual outdoor temperature The reset function works as shown in Figure 24 When the outdoor air temperature reaches the high outdoor t...

Page 31: ...then the boilers will simultaneously drop their firing rate If when reaching the point where both boilers drop toward their minimum firing rate 20 then the first slave will drop out Slave1 will remai...

Page 32: ...energize for pre purge then the ignition sequence starts After all safety devices are verified the gas valve opens If ignition doesn t occur turn off the Mascot II check that there is SECTION 10 Oper...

Page 33: ...can be forced to low fire to allow for easier setup Refer to Section 8 1 Table 11 for instructions on how to access the forced rate menu CO2 readings should be between the values shown in Table 13 If...

Page 34: ...LAARS Heating Systems Page 34 GAS TYPE HIGH FIRE CO2 LOW FIRE CO2 Natural 9 0 9 0 Propane 10 0 10 0 Table 13 CO2 Range Figure 25 Adjustment Screws and Settings for CO2...

Page 35: ...e Pump 11 2 1 Burner Check the burner for debris Remove the blower arm assembly to access the burner Remove the 4 bolts connecting the blower to the arm see Figure 32 Remove the 5 bolts which hold the...

Page 36: ...e soot deposits with a wet brush or fine water spray before servicing the heat exchanger 1 Shut off the 120 Volt power supply to the boiler 2 Turn off all manual gas valves connecting the boiler to th...

Page 37: ...um input CO2 Any high fire adjustment may affect low fire settings Screws for adjustment are shown in Figure 26 7 Reinstall front cover SECTION 12 Trouble Shooting 12 1 Sequence of Operation Mascot II...

Page 38: ...92 Outlet sensor fault 93 DHW sensor fault Faulty sensor or wiring Check wiring replace sensor condition can be 95 Stack sensor fault caused by short 96 OAT temperature sensor fault Faulty outdoor ai...

Page 39: ...values min 12 C 22 F to a difference greater than 22 F 12 C 255 CH setpoint minus ODR Increase Outdoor water min water temperature was temperature min and max too small min 12 C 22 F values to a diff...

Page 40: ...ral Information To order or purchase parts for the LAARS Mascot II contact your nearest LAARS dealer or distributor If they cannot supply you with what you need contact Customer Service see back cover...

Page 41: ...1 4 npt E2337500 8O Exchanger heat plate 8P Tie cable 14 3 4 long x 0 31 wide heat stabilized F2029100 8Q Flow switch water E2337400 8R Pipe tailpiece 1 npt M x 3 4 tube cu 12H4023 8S O ring 120 1 ID...

Page 42: ...LAARS Heating Systems Page 42 Figure 28 Panel Assembly Door Top...

Page 43: ...Mascot II Boilers and Water Heaters Page 43 Figure 29 Panel Assembly Door Middle...

Page 44: ...LAARS Heating Systems Page 44 Figure 30 Panel Assembly Door Bottom...

Page 45: ...Mascot II Boilers and Water Heaters Page 45 Figure 31 Base Jacket Assembly...

Page 46: ...LAARS Heating Systems Page 46 Figure 32 Heat Exchanger Cabinet Fan...

Page 47: ...Mascot II Boilers and Water Heaters Page 47 Figure 33 Heat Exchanger Burner Components...

Page 48: ...LAARS Heating Systems Page 48 Figure 34 Pump Assembly Components...

Page 49: ...Mascot II Boilers and Water Heaters Page 49 Figure 35 Plumbing Components...

Page 50: ...LAARS Heating Systems Page 50...

Page 51: ...Mascot II Boilers and Water Heaters Page 51...

Page 52: ...Fax 603 335 3355 Applications Engineering 1869 Sismet Road Mississauga Ontario Canada L4W 1W8 905 238 0100 Fax 905 366 0130 www Laars com Litho in U S A Laars Heating Systems 1111 Document 1230A Dime...

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