Section 1: Introduction
1-1 System.
1-1.1The MURPHYMATIC® Generator Engine Control System, Series A900 is designed to meet the requirements of the engine control, shutdown and alarm section of NFPA-110 “Emergency And Standby Power Systems” specification. The controller also meets the minimum requirements of NFPA99 “Health Care Facilities” and the Canadian standard CAN/CSA-C282-M89 “Emergency Electrical Power Supply for Buildings” for engine control, shutdown and alarm systems. By combining one of the A900 series controls with generator instruments, a complete engine generator control panel meeting the above specifications can be provided.
1-2 Models.
1-2.1The Series A900 is available in three basic configurations:
1-2.1.1Model A901 for automatic start and stop generator sets which includes the minimum shutdowns and alarms per NFPA- 110 Level 1.
1-2.1.2Model A902 for automatic start and stop generator sets which includes the minimum shutdowns and alarms per NFPA- 110 Level 2.
1-2.1.3Model A903 for automatic start and stop generator sets which includes the minimum shutdowns and alarms per NFPA- 110 Level 2 and seven unlabeled alarm lights for additional customer specified alarms.
1-2.2All models are available for 12 or 24 V DC operation.
1-2.3All models are available for use on either two cycle or four cycle engines. Models for two cycle engines include an alarm light for “Air Damper Closed” and an “Overspeed Relay” to operate the air shutoff solenoid for overspeed shutdown.
1-2.4Each model is made up of two parts, a Control/Display module and a Relay module.
1-3 Purpose.
1-3.1This manual is directed to the installation, maintenance and operating personnel who will be in day to day contact with the A900 system. However the basic knowledge gained with this material will allow those personnel to easily adjust to special circumstances.
1-4 Definitions.
1-4.1Throughout this manual, reference is made to organi- zations, trade names and trademarks which may not be familiar to the reader. Some of these are:
1-4.1.1CSA: Canadian Standards Association.
1-4.1.2CAN/CSA-C282-M89: The standard for Emergency Electrical Power Supply for Buildings, 1989 Edition.
1-4.1.3NFPA: National Fire Protection Association.
1-4.1.4NFPA-70: The National Electrical Code.
1-4.1.5NFPA-99-1990: The standard for Health Care Facilities, 1990 Edition.
1-4.1.6NFPA-110-1988: The standard for Emergency And Standby Power Systems, 1988 Edition.
1-4.1.7Several terms used in this manual are registered trademarks of Frank W. Murphy Mfr.
(a)MURPHYMATIC® : Refers to all Murphy automatic controls.
(b)SELECTRONIC® : A name that is applied to all electronic controls manufactured by Murphy.
(c)SWICHGAGE® : A combination indicating gauge and switch.
(d)TATTLETALE® : A term that refers to a shutdown indicating device or circuit in the control panel.
1-5 How to use this manual.
1-5.1Section 1, 2, 4, 5, 6 and 7 contain general information that applies to all A900 models.
1-5.2Section 3, Model Identification, is broken into seven sub sections. Section 3-1 allows you to chose the model that best fits your requirements and Section 3-2 through 3-7 explain each models features in detail.
Section 2: Specifications
2-1 Enclosure Type.
2-1.1The A900 Series enclosure is designed to be mounted in a standard electrical enclosure for indoor use.
2-2 Power Requirements.
2-2.1The engine controls, shutdown circuits, alarm and shut- down indicators are powered from the engine starting battery. The A900 series is available in either 12 or 24 V, negative ground. 2-2.2The A900 is fused for 3 A maximum current.
2-3 Input Ratings.
2-3.1All input switches should be dry contact type, maximum current is 2 mA, 8 V DC or less.
2-3.2Frequency signal for the speed sensing circuit requires a minimum input of 2 V rms from a magnetic pickup (preferred) or from the tachometer terminal of the battery charging alternator.
2-3.2.1Frequency range of the speed sensing circuits is 25 Hz to 10,000 Hz.
2-4 Output Ratings.
2-4.1The A900 Control / Display Module has outputs for remote indication of alarm and shutdowns. These outputs are transistors that close to the negative supply (sink) and are rated at 1 amp, 30 V DC maximum.
2-4.2The Control / Display Module also has an output for an auxiliary starter contactor which is rated 1 A, 30 V DC maximum. This is a transistor that closes to the positive supply (source).
2-4.3The Relay Module includes 3 engine control relays with contact ratings of 7 A, 30 V DC inductive. These powered contacts must be supplied from an 8 A fuse or circuit breaker (customer supplied). The 3 alarm relays have dry contacts, also rated at 7 A, 30 V DC maximum.
2-5 Field Wiring Connections.
2-5.1All field wiring connections are barrier terminal blocks, UL rated for 15 A, 300 V.
2-6 Operating Temperature.
2-6.1The operating temperature range of the A900 is -4°F to 158°F (-20°C to 70°C.)
Section 3: Model Identification
3-1 Model Numbers.
3-1.1A901-12 and A901-24: These models are designed for an automatic start four cycle engine driven generator, and include the shutdown and alarm points recommended in NFPA- 110-1988 “Emergency and Standby Generator Systems” for Level 1 installations. These controllers also meet or exceed the minimum requirements of NFPA99-1990 “Health Care Facilities” and with the addition of a Low Water Level alarm, the Canadian standard CAN/CSA-C282-M89 “Emergency Electrical Power Supply for Buildings”. The suffix numbers -12 and -24 indicate the engine starting battery voltage.
3-1.2A901-2-12 and A901-2-24: These models are designed for
