The Honeywell EC7890A,B/RM7890 is a microprocessor based integrated burner control for automatically fired gas, oil or combination fuel single burner applications. The EC/RM7890 system consists of the Relay Module, Subbase and Amplifier. Options include Keyboard Display Module (KDM), Personal Computer Interface, Data ControlBusô Module, Remote Display Module, First-Out Expanded Annunciator and COMBUSTION SYSTEM MANAGER Software.
The EC/RM7890 is programmed to provide a level of safety, functional capability and features beyond the capacity of conventional controls.
Functions provided by the EC/RM7890 include automatic burner sequencing, flame supervision, system status indication, system or self-diagnostics and troubleshooting
FEATURES
• Safety features:
- Closed loop logic test.
- Dynamic AMPLI-CHECK.
- Dynamic input check.
- Dynamic safety relay test.
- Dynamic self-check logic.
- Expanded safe-start check.
- Internal hardware status monitoring.
- Tamper resistant timing and logic.
• Access for external electrical voltage checks.
• Application flexibility. ï Communication interface capability (optional).
• Dependable, long-term operation provided by microcomputer technology.
• First-out annunciation and system diagnostics are provided by a 2 row by 20 column Vacuum Fluorescent Display (VFD) located on the optional Keyboard Display Module.
• First-out expanded annunciation with 26 Light Emitting Diodes (LEDs) for limits and interlocks (optional). ï Five (LEDs) for sequence information. (See Fig. 1.)
• Interchangeable plug-in flame amplifiers.
• Local or remote annunciation of RM7890 operation and fault information (optional).
• Nonvolatile memory; EC/RM7890 retains history files and sequencing status after loss of power.
• Provides 0.8 or 3.0 second FFRT, depending on amplifier selected. EC7890A1029, EC7890B1028 are 1.0 or 2.0 second FFRT. ï Remote reset (optional).
• Report generation (optional).
• Selectable relight (0.8 second FFRT amplifier only) or lockout on loss of flame.
• Shutter drive output (EC/RM7890B).
• Burner controller data (optional):
- Expanded annunciator status.
- Flame signal strength.
- Hold status.
- Lockout/alarm status.
- Sequence status.
- Sequence time.
- Total cycles of operation.
- Total hours of operation.
- Fault history providing the six most recent faults:
• Cycles of operation at the time of the fault.
• Expanded annunciator data at the time of the fault. ï fault message and code.
• Hours of operation at the time of the fault.
• Sequence status at the time of the fault.
•Sequence time at the time of the fault.
- Diagnostic information:
• Device type.
• Flame amplifier type.
• Flame failure response time.
• Manufacturing code.
• On/Off status of all digital inputs and outputs.
• Software revision and version of RM7890 and optional Keyboard Display Module.
• Status of configuration jumpers.
Table 1. Sequence Timing For Normal Operation.
| Device |
Initiate |
Standby |
Pilot Flame Establishing Period (PFEP) |
Run |
| EC7890A/RM7890A |
10 seconds |
* |
4 or 10 seconds |
* |
| EC7890B/RM7890B |
10 seconds |
* |
4 or 10 seconds |
* |
| RM7890C |
10 seconds |
* |
Standing Pilot |
* |
*STANDBY and RUN can be an infinite time period.
Table 2. Terminal Ratings.
| Terminal Number |
Description |
Ratings (RM7890A,B,C) |
Ratings (EC7890A,B) |
| G |
Flame Sensor Ground |
- |
- |
| Earth G |
Earth Grounda |
- |
- |
| L2(N) |
Line Voltage Common |
- |
- |
| 3 |
Line Voltage Supply (L1) |
120 Vac (+10%/-15%), 50 or 60 Hz
(±10%)b |
220 to 240 Vac (+10%/-15%), 50 or
60 Hz (±10%) |
| 4 |
Alarm |
120 Vac, 1A pilot duty. |
220 to 240 Vac, 1A pilot duty. |
| 5 |
Unused |
- |
- |
| 6 |
Burner Control and Limits |
120 Vac, 8A run, 43A inrush. |
220 to 240 Vac, 5A (maximum) |
| 7 |
Unused |
- |
- |
| 8 |
Pilot Valve/Ignition |
120 Vacc |
220 to 240 Vac,
4A at P.F. = 0.5, 20A inrush |
| 9 |
Main Fuel Valve |
120 Vacc |
220 to 240 Vac,
4A at P.F. = 0.5, 20A inrush |
| 10 |
Ignition |
120 Vac, 4.5A ignition.d |
220 to 240 Vac, 4A at P.F. + 0.2 |
| F(11) |
Flame Sensor |
60 to 220 Vac, current limited. |
60 to 220 Vac, current limited. |
| 12 to 21 |
Unused |
- |
- |
| 22 |
Shutter |
120 Vac, 0.5A (RM7890B). |
220 to 240 Vac (EC7890B only)d |
a The RM7890 must have an earth ground providing a connection between the subbase and the control panel or the equipment.
The earth ground wire must be capable of conducting the current to blow the 15A fuse (or breaker) in event of an internal short
circuit. The RM7890 needs a low impedance ground connection to the equipment frame which, in turn, needs a low impedance
connection to earth ground. For a ground path to be low impedance at RF frequencies, the connection must be made with minimum length conductors having maximum surface areas. Wide straps or brackets rather than leadwires are preferred. Be careful to verify that mechanically tightened joints along the ground path, such as pipe or conduit threads or surfaces held together
with fasteners, are free of nonconductive coatings and are protected against mating surface corrosion.
b 2000 VA maximum connected load to RM7890 Assembly.
c See Tables 3 and 4 for device load combinations.
d Requires 220-240 to 120 Vac, 10 VA minimum stepdown transformer to drive shutter.
Table 3. Combinations for terminals 8, 9, and 10.
| Combination Number |
Pilot Fuel
8 |
Main
9 |
Ignition
10 |
| 1 |
C |
F |
No Load |
| 2 |
B |
F |
No Load |
| 3 |
No Load |
F |
No Load |
| 4 |
F |
F |
A |
| 5 |
No Load |
F |
A |
| 6 |
D |
F |
A |
| 8 |
D |
D |
A |
| 9 |
No Load |
D |
A |
Table 4. Composition of each combination.
| A. |
B. |
C. |
D. |
F. |
| 4.5A ignition |
50 VA Pilot Duty
plus 4.5A Ignition. |
180 VA Ignition plus Motor
valves with:
660 VA inrush, 360 VA
open, 250 VA hold. |
2A Pilot Duty. |
65 VA Pilot Duty plus Motor valves
with:
3850 VA inrush, 700 VA open, 250 VA
hold. |
Electrical Ratings, see Table 1:
Voltage and Frequency:
RM7890A,B,C: 120 Vac (+10/-15%), 50 or 60 Hz (±10%).
EC7890A,B: 220 to 240 Vac (+10/-15%), 50 or 60 Hz (±10%).
Power Dissipation: RM7890: 10W maximum.
Maximum Total Connected Load: 2000 VA.
Fusing: Total Connected Load: 15A maximum, type SC or equivalent, fast blow.
Environmental Ratings:
Ambient Temperature:
Operating: -40°F to +140°F (-40°C to +60°C).
Storage: -40°F to +150°F (-40°C to +66°C).
Humidity: 85% RH continuous, noncondensing.
Vibration: 0.5G environment.
Dimensions: Refer to Fig. 2.
Weight:
EC7890/RM7890 with Dust Cover: 1 pound 13 ounces (822 grams), unpacked.
IMPORTANT
Flame Detection System available for use with EC7890/RM7890. To select your Plug-in Flame Signal Amplifier and applicable Flame Detector, see Table 5.
Dimensions
Accessories:
Keyboard Display Modules (KDM):
S7800A1001 English language.
S7800A1035 French language.
S7800A1043 German language.
S7800A1050 Italian language.
S7800A1068 Spanish language.
S7800A1118 Katakana (Japanese) language.
S7800A1126 Portuguese language.
Communications:
Q7700A1014 Network Interface Unit, 120 Vac, 50/60 Hz applications, external modem required.
Q7700B1004 Network Interface Unit with universal 100 to 250 Vac, 50/60 Hz external power supply, external modem required.
QS7800A1001 ControlBus Module, standard.
QS7800B1000 ControlBus Module, multidrop.
QS7850A1006 ControlBus Module, General Purpose Interface.
ZM7850A1001 Combustion System Managerô software.
S7810A1009 Data ControlBus Module (if no KDM is used).
S7810B1007 Data ControlBus Module, Multi-Drop Switch Module.
S7810M1003 ModBus Module.
S7810M1029 ModBus Module for EC7890A1029, EC7890B1028.
Miscellaneous:
A7800A1002 7800 SERIES Tester.
S7820A1007 Remote Reset Module.
S7830A1005 Expanded Annunciator, 120 Vac, 50/60 Hz.
221729 Dust Cover, Relay Module.
123514A Rectification Flame Simulator.
203659 Ultraviolet Flame Simulator.
Table 5. Flame Detection Systems.
| Plug-in Flame Signal Amplifiers |
Applicable Flame Detectors |
| Type |
Color |
Self-Checking |
Model |
Flame
Failure
Response
Time (sec)a |
Fuel |
Type |
Models |
| Rectification |
Green |
Dymanic Self-Check |
R7824Cb,c,hi |
3 |
Gas, oil,
coal |
Ultraviolet (Purple
Peeper) |
C7024E,F |
| No |
R7847Ag |
0.8/1 or 2/3 |
Gas |
Rectifying Flame Rod
Holdersj |
C7004, C7007, C7011
Complete Assemblies:
C7008, C7009, Q179 |
| No |
R7847Ag |
2/3 |
Gas, oil,
coal |
Ultraviolet (Purple
Peeper) |
C7012A,C. |
Dynamic Ampli-
Check |
R7847Bd,g |
0.8/1 or
2/3 |
Gas |
Rectifying Flame Rod
Holdersb |
C7004, C7007, C7011
Complete Assemblies:
C7008, C7009, Q179 |
Dynamic Ampli-
Check |
R7847Bd,g |
2/3 |
Gas, oil,
coal |
Ultraviolet (Purple
Peeper) |
C7012A,C |
| Dynamic Self-Check |
R7847Cc,e,h |
2/3 |
Gas, oil,
coal |
Ultraviolet (Purple
Peeper) |
C7012E,F |
| Infrared |
Red |
No |
R7848A |
2/3 |
Gas, oil,
coal |
Infrared (Lead
Sulfide) |
C7015 |
Dynamic Ampli-
Check |
R7848Bd |
3 |
Gas, oil,
coal |
Infrared (Lead
Sulfide) |
C7015 |
| Ultraviolet |
Purple |
No |
R7849A |
0.8/1 or
2/3 |
Gas, oil |
Ultraviolet
(Minipeeper) |
C7027, C7035, C7044f |
Dynamic Ampli-
Check |
R7849Bd |
0.8/1 or
2/3 |
Gas, oil |
Ultraviolet
(Minipeeper) |
C7027, C7035, C7044f |
| Dynamic Self-Check |
R7861Ac,e |
0.8/1 or
2/3 |
Gas, oil,
coal |
Ultraviolet |
C7061 |
| Blue |
Dynamic Self-Check |
R7886Ac,e |
2/3 |
Gas, oil,
coal |
Ultraviolet (Adjustable
Sensitivity) |
C7076 |
| Optical |
White |
Dymanic Ampli-
Check |
R7851B |
0.8/1 or 2/3 |
Gas, oil,
coal |
Optical (UV, IR,
Visible Light) |
C7927, C7935, C7915,
C7962 |
| Dynamic Self-Check |
R7851Cc |
2/3 |
Gas, oil,
coal |
Optical (UV only) |
C7961 |
a Flame Failure Response Time (FFRT) depends on selection of amplifier and 7800 SERIES Relay Module.
b R7824C is used only with the 24 Vdc RM7824 Relay Module and C7024E,F Flame Detectors.
c Circuitry tests all electronic components in flame detection system (amplifier and detector) 12 times a minute during burner operation and shuts down burner if detection system fails.
d Circuitry tests flame signal amplifier 12 times a minute during burner operation and shuts down burner if amplifier fails.
e 200/220/240 Vac applications require a 120 Vac, 10 VA minimum stepdown transformer (not provided) to drive the shutter. Applies to R7847C series 3 or greater; R7886A series 2 or greater; R7861 series 1 or greater. Fig. 2 shows flame detector wiring.
f Use C7027, C7035 and C7044 Flame Detectors only on burners that cycle on-off at least once every twenty-four hours. Use C7012E,F Flame Detector with R7847C Amplifier, C7061A Ultraviolet Detector with R7861A Amplifier or C7076A Flame Detector with R7886A Amplifier as ultraviolet flame detection system for appliances with burners that remain on continuously for twenty-four hours or longer.
g R7847A,B Amplifiers with 0.8/1 second FFRT should not be used with C7012A,C Solid State Ultraviolet Detectors.
h R7824C Series 2 and greater and R7847C Series 4 and greater check flame detector system when flame reaches 1.5 Vdc or at 4.5 seconds, whichever occurs first.
i Order flame rod separately; see flame detector Instructions for holder.
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