49.When power is sent to gas valve 1 it is also sent to time delay relay 1 (TD-1) which starts a 5-second countdown.

50.After the 5-second countdown from TD-1 and the internal contacts close, time delay relay 2 (TD-2 ) receives 24 VAC.

51.Gas valve 1a is energized allowing the remainder of stage 1 to fire.

52.After the 5-second countdown from TD-2 the inter- nal contacts close allowing 24 VAC to sit at pin 3 of the stage 2 connection on the CPW board.

53.After closure of the stage 2 contacts Gas valve 2 is energized.

54.The stage 2 LED on the status display board is now illuminated.

55.The temperature controller closes the stage 3 con- tacts at J3 on the CPW board.

56.Power is applied to pin 5 of the stage 3 connec- tions on the CPW board.

57.Power is applied to the “TH” terminal of ignition module 2.

58.Once the “TH” signal is received at ignition module 2, the heater will perform a 15-second pre-purge, and then hot surface igniter 2 is energized by a 120 VAC signal from S-1 on ignition module 2 for approximately 30 seconds. (The hot surface ignit- er must draw greater than 3.1 amps while being energized or ignition lockout will occur after three tries.)

59.If ignition module two locks out, a signal will be sent to the Universal Diagnostics Board and to the status display board to indicate an ignition fault.

60.Once the ignition module determines that the hot surface igniter has heated up and operating prop- erly, a 24 VAC signal is output from pin GV on the module.

61.24 VAC signal is received at gas valve 3 thus ener- gizing it.

62.The stage 3 LED on the status display board is now illuminated.

63.The coil of relay K-5 (N.O.) is now energized with the (K-5) contacts closing downstream of the stage 4 connections.

64.Remote flame sensor 2 is trying to rectify flame.

65.Power is now applied to time delay relay 3 and the contacts of TD-3 located upstream of the stage 4 connection close after 5 seconds.

66.The stage 4 controller contacts close.

67.Power is applied to gas valve 4.

68.The stage 4 LED on the status display board is now illuminated.

69.The heater is now operating at full fire.

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Raypak 992B manual
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992B specifications

The Raypak 992B is a highly regarded commercial boiler known for its efficiency and reliability in heating applications. Designed for a range of installations, it is particularly favored in schools, hotels, and various commercial settings where dependable heating is crucial. One of the standout features of the Raypak 992B is its impressive thermal efficiency rating, often exceeding 90%. This efficiency translates into lower energy costs and reduced environmental impact, making it a smart choice for eco-conscious businesses.

The Raypak 992B comes equipped with advanced technologies that enhance performance and ease of use. Among these technologies is the high-precision digital control system, which allows for accurate temperature regulation and monitoring. This feature ensures optimal performance and minimizes energy waste, further contributing to the unit's cost-effectiveness. The boiler also utilizes a modulating burner system, enabling it to adjust flame size based on real-time heating demands. This adaptability not only enhances efficiency but also improves overall comfort within a facility.

Another significant characteristic of the Raypak 992B is its robust construction. Built with durable materials designed to withstand demanding operating conditions, this boiler is engineered for long-lasting performance. Its compact design is an added benefit, facilitating installation in areas with limited space. The unit is also equipped with a stainless steel heat exchanger, which provides superior resistance to corrosion and enhances heat transfer efficiency.

Safety features are also paramount in the design of the Raypak 992B. The boiler includes multiple safety controls and alarms to prevent overheating and maintain safe operating conditions. This diligence in safety ensures peace of mind for operators and reduces the risk of unexpected downtime.

In summary, the Raypak 992B stands out as a top choice for commercial heating solutions, combining high efficiency, advanced technology, and rugged construction. Its features cater to a wide range of heating needs while prioritizing safety and economy. With its impressive performance capabilities, the Raypak 992B continues to be a reliable partner for facilities seeking optimal heating solutions.
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