Crown Boiler MAXI-THERM MT040G, Инструкция по установке и эксплуатации

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The following general notes apply to all wiring:
1) Wiring must be done in accordance with all codes. In the absence of any codes, the system must be wired
in accordance with the National Electric Code (ANSI/NFPA 70-latest edition).
2) The control system for the boiler, Maxi-Therm, and heating zones must be on a dedicated circuit. The
current rating of this circuit will depend on the total number and size of loads in the system, however it
should in no case be less than 15 AMPS.
3) The Maxi-Therm is equipped with Honeywell L4006A series thermostat. This thermostat has a set of
contacts, which make upon a call for domestic water and break when this temperature is satisfied.
CIRCULATOR ZONE WIRING (NON PRIORITY)
Figure 16 is a connections diagram for a non-priority circulator zone system using Honeywell R845A’s.
The R845A is equipped with two sets of contacts (3,4, and 5,6) which become made when the T and T
terminals are made. Terminals 1 and 2 on the R845A are supplied with 110 VAC to power its internal
transformer. In this application, one R845A is provided for each zone including that of the Maxi-Therm. If
the boiler has a factory-equipped circulator, this is disconnected from the circulator terminals on the boiler.
When any thermostat (including the thermostat on the Maxi-Therm) calls for heat, the relay in the R845A
for that zone becomes energized. Terminals 3 and 4 become “made”, energizing the circulator. Terminals 5
and 6 are also made which start the boiler.
CIRCULATOR ZONE WIRING (PRIORITY)
Figure 17 is a connections diagram for priority circulator zoning. This system is similar to non-priority
circulator zoning, except that a Honeywell R8285B fan center is used in place of the R845A on the Maxi-Therm
zone. This fan center consists of a DPDT relay and a 24 volt transformer. The Maxi-therm control is connected
to terminals R and G so that when the Maxi-therm control calls for heat the relay is energized.
One set of contacts on the R8285B is used to switch line voltage. On this set of contacts, the common is
connected to an unswitched “hot”. The normally closed contact is connected to terminal #1 on each of the
space heating zone’s R845A’s. The normally open contact is connected to the Maxi-therm zone circulator.
The normally closed contact on the other set of R8285B contact is not used. The common and normally open
contacts are connected in parallel with terminals #5 and #6 on the space-heating zone R845A’s.
As long as the Maxi-therm zone does not call for heat, the R845As for the heating zones have 110 VAC
across their 1 and 2 terminals and the heating zones will function as described in the non-priority circulator
zone section. As soon as the Maxi-therm calls for heat, however, the normally closed terminals in the
R8285B open, de-energizing the heating zones and energizing the Maxi-therm circulator. The other set of
contacts in the R8285B (connected across the boiler thermostat connections) become “made”, which brings on
the boiler.
ZONE VALVES (NON PRIORITY) Figure 18 is a connections diagram for a zone system using Honeywell
V8043F motorized zone valves. The motor on these valves is connected between TH and TR. TH/TR is
provided for the electrician’s convenience as a binding post and is not connected to anything inside the valve.
The “endswitch” terminals are connected to a set of switch contacts inside the valve, which become made
when the valve is open.
A call for heat from any thermostat or the Maxi-therm aquastat results in the application of 24-volts across
the motor in that zone’s zone valve. This drives open the zone valve. When the valve has opened, the
endswitch in that zone valve makes and brings on the boiler.
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