HydroTherm MultiTemp MR Series, Инструкция по установке и перечень запасных частей, Страница: 29 / 36

RETURN
SUPPLY
SUPPLY WATER
TEMP. SENSOR
MANUAL RESET
HI-LIMIT
ELECTRONIC
LOW WATER
CUTOFF
SAFETY
HI-LIMIT
TO "S"
CONTROL
TO "S"
CONTROL
TO "S"
CONTROL
TO "S"
CONTROL
TO "S"
CONTROL
TO "S"
CONTROL
FIGURE C4: EXAMPLE OF LEVEL III CONTROL WITH MODEL "S" CONTROL FOR SPACE HEATING ONLY
When outdoor temperature falls below setting of outdoor temperature sensor, the circulator and Model "S" control circuits are energized. The Model "S" control will begin to
fire boiler modules until sufficient temperature is present at the supply water temperature sensor to meet the demands of the Model "S" control. As the outdoor air tempera-
ture (as detected by the outdoor temperature sensor) decreases, the Model "S" control again causes modules to fire, until a higher supply water temperature is reached.
GAS VALVE
CIRCULATOR
24V TRANSFORMERS
H N
115V
TO "S"
CONTROL
TO "S"
CONTROL
TO "S"
CONTROL
MODEL "S" CONTROL
FOR WIRING CONNECTIONS,
FOLLOW INSTRUCTIONS
IN S2 INSTALLATION MANUAL
PACKAGED WITH CONTROL
L1
L2
B
B
NOTE: CONTROLS (THERMOSTATS, LOW WATER
CUT-OFFS, AQUASTATS) ARE RATED AT 8 AMP.-120V,
5.1 AMP.-240V (1/2 HP). WHEN CIRCUIT POWER
EXCEEDS THIS, CONTACTORS MUST BE USED. 24V
TRANSFORMER MUST HAVE 60VA MINIMUM RATING.
OUTDOOR
TEMP. SENSOR
FIGURE C5: EXAMPLE OF LEVEL I CONTROL FOR COMBINATION SPACE & SERVICE WATER HEATING
Two modules maintain service hot water by dual modulating aquastat mounted in heat exchanger for year-round operation. When outdoor temperature drops below its
setting, outdoor thermostat energizes system circulator and remaining two modules to provide heat to heating system. If water temperature in the heat exchanger drops
below a pre-set minimum, reverse acting aquastat cuts out circulator until temperature rises above minimum. Single pole relay ensures that heating system boilers do
not fire without circulator being energized.
SUPPLY
CIRCULATOR
OUTDOOR
THERMOSTAT
(SYSTEM
STARTER)
DUAL AQUASTAT
(#1 SET AT 170F, #2 SET AT 175F)
DUAL
AQUASTAT
REVERSE ACTING
AQUASTAT
RETURN
ELECTRONIC
LOW WATER
CUTOFF
MANUAL RESET
HI-LIMIT
OUTDOOR BULB
(LOCATED ON
NORTH WALL)
SUNSHIELD
B
L2
L1
B
SINGLE
POLE
RELAY
w/ 120V
COIL
24V TRANSFORMERS
H
N
115V
NOTE: CONTROLS (THERMOSTATS, LOW WATER
CUT-OFFS, AQUASTATS) ARE RATED AT 8 AMP.-120V,
5.1 AMP.-240V (1/2 HP). WHEN CIRCUIT POWER
EXCEEDS THIS, CONTACTORS MUST BE USED. 24V
TRANSFORMER MUST HAVE 60VA MINIMUM RATING.
SAFETY
HI-LIMIT
GAS VALVE
29