Page 47
7.D
Optional Field Connections
Terminal block 8 (TB8) in the control panel is used for the ‘Safety
Chain’ and for connecting optional components such as low water
cutoffs, flow switches, additional high limits, and other field-supplied
devices that must be interlocked with the boiler. These are non-
powered dry contacts only. All safeties or end switches must be
wired in series by removing the supplied jumpers.
See Figure 33
NOTE: When installing any field-supplied options like Low Water
Cutoff, High Limits, or a Flow Switch, always remove the jumper that
is factory installed at that location on the TB8 block.
7.C Hydronic Heating Using External Modulation
Control
About External Control -
When the unit is used for hydronic heating with external modulation
control, a call for heat must be supplied to the “T-T or Interlock”
terminal. Once the call is supplied the control starts the Boiler and
System pumps and begins the ignition process. Once in Run, the
unit monitors the flame signal, call for heat, safeties, and water
temperatures. The boiler setpoint is used to limit the maximum water
temperature leaving the boiler only. The modulation rate is controlled
by a 4-20mA signal supplied by an external control. (This can also
be 0-10Vdc using a converter - part number CA006100.) When
setting up a system using an external control, take care to set Anti-
Short Cycle feature to prevent “hunting “ and possible premature
component failure.
Table 16.
Boiler and Pump Electrical Data
Table 17.
Water Heater and Pump Electrical Data
If amp draw exceeds 7.4A max, an external pump contactor will be required.
All Boiler, Water Heater and Pump Circuits are 120V.
MMERCIAL NEOTHERM MANUAL H2374
Boiler
Size - MBH
399-500
600-850
150-399
500
600-850
FLA
< 4 amp
5 amp
< 4 amp
6 amp
12 amp
MCA
< 4 amp
6 amp
5 amp
8 amp
15 amp
MOP
5 amp
11 amp
8 amp
14 amp
27 amp
Boiler Electrical Data
Water Heater
Size - MBH
150-500
600-850
150
199-500 600-850
FLA
< 4 amp
5 amp
< 4 amp
6 amp
12 amp
MCA
< 4 amp
6 amp
5 amp
8 amp
15 amp
MOP
5 amp
11 amp
8 amp
14 amp
27 amp
Water Heater Electrical Data
If amp draw exceeds 7.4A max an external pump contactor will be required. All Boiler, Water Heater, and Pump circuits are 120V.
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MMERCIAL NEOTHERM MANUAL H2374
Boiler
Size - MBH
399-500
600-850
150-399
500
600-850
FLA
< 4 amp
5 amp
< 4 amp
6 amp
12 amp
MCA
< 4 amp
6 amp
5 amp
8 amp
15 amp
MOP
5 amp
11 amp
8 amp
14 amp
27 amp
Boiler Electrical Data
Water Heater
Size - MBH
150-500
600-850
150
199-500 600-850
FLA
< 4 amp
5 amp
< 4 amp
6 amp
12 amp
MCA
< 4 amp
6 amp
5 amp
8 amp
15 amp
MOP
5 amp
11 amp
8 amp
14 amp
27 amp
Water Heater Electrical Data
If amp draw exceeds 7.4A max an external pump contactor will be required. All Boiler, Water Heater, and Pump circuits are 120V.
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N
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HERM
Commercial Boilers and Water Heaters
Summary of Contents for NEOTHERM NTH
Page 4: ...LAARS Heating Systems ...
Page 36: ...Page 36 Figure 22 Hydronic Piping Single Boiler Zoning with Circulators LAARS Heating Systems ...
Page 52: ...Page 52 Figure 36 Ladder Diagram 7 H Ladder Diagram LAARS Heating Systems ...
Page 100: ...Page 100 Parts Illustration 4 Internal Components Sizes 750 850 LAARS Heating Systems ...
Page 102: ...Page 102 Parts Illustration 6 Gas Train Components Sizes 600 850 LAARS Heating Systems ...