Siemens Actuator SKP 55 001E2

Technical Instructions Document No. 155-753 SKP55 U.. July 9, 2014 SKP Series SKP55 U.. Air/Gas Ratio Controlling Actuators With Safety Shutoff Function For Use with Gas Valves VG Description SKP55 pressure regulating electro-hydraulic actuators combine with VG series gas valves to provide slow opening, fast closing safety shut-off and air/gas ratio control for industrial and commercial burner applications. The SKP55 actuator controls the pressure difference across a restriction in the gas supply line as a function of the pressure difference across a restriction in the air supply duct so that the air to gas ratio remains constant irrespective of air volume changes. There is no need for an upstream constant pressure regulator when using an SKP55 actuator within the applicable pressure range of the VG valve body. Since a single valve performs three functions: safety shut-off, constant pressure regulation, and air/gas ratio control, fewer components and fittings are required to assemble a gas train. This significantly reduces both the size and the weight of the gas train. The total pressure drop across the gas train arrangement is reduced, allowing for the use of smaller diameter gas trains in most applications. The modular design allows the SKP55 actuator to be used in combination with all VG series gas valves from 1/2-inch to 6-inch in size. The actuator is easily mounted on the square flange of any VG valve with four bolts. No gaskets or seals are required when mounting the actuator. A visible position indicator on the front of the actuator displays the entire stroke of the valve. A light indicates when the actuator is powered. Siemens Building Technologies, Inc. Technical Instructions SKP55 U.. Air/Gas Ratio Controlling Actuators Document No. 155-753 July 9, 2014 Features • UL listed, FM approved, CSA certified for USA and Canada, and ISO 9001 certified; European, Australian and Japanese approved versions available. • Safety shut-off function, pressure regulating function and air/gas ratio control in one compact unit. • Proof Of Closure with Over Travel (POC) versions. • Simplifies commissioning and reduces start-up time for: o Recuperative burners with combustion air preheating. o Burners with continuously variable air or gas nozzle openings in the burner head. o Burners where either the air or gas pressure is not representative of the actual flow. o Burners with negative combustion air pressure levels. • Maintains air/gas ratio when the airflow is disrupted. • Automatic compensation for combustion chamber back pressure fluctuations. • No mechanical wear or play that causes drifting. • Visual stroke position indicator. • Light indicating "power on". • Optional auxiliary switch available. • ) Excellent tracking characteristic. • Low, 13.5 VA power consumption. Application SKP55 series actuators may be combined with 1/2-inch to 6-inch VG series gas valve bodies. VG series gas valves are ordered as separate items (See VG U.. Technical Instructions P/N 155-512P25). Product Numbers Table 1. Product Number Operating Proof of Closure Auxiliary Switch Type of Switch Voltage Switch SKP55.011U1 x – SPDT SKP55.012U1 110 to 120 Vac x x SPDT SPDT SKP55.013U1 – – SKP55.012U2 x x SPDT SPDT 220 to 240 Vac SKP55.013U2 – – Accessories Table 2. Product Number Description AGA66 Sealing gasket to provide NEMA 3, 3R, and 4 protection (for VGG/D valves) Page 2 Siemens Building Technologies, Inc. SKP55 U.. Air/Gas Ratio Controlling Actuators Technical Instructions Document No. 155-753 July 9, 2014 Specifications As safety shut-off valve UL/429, FM/7400, ANSI Z21.21/CSA6.5 C/I in combination with VG U.. series gas valves Agency approvals As a pressure regulator ANSI Z21.18/CSA6.3 Power supply Operating voltage 110 to 120 Vac + 10% to 15% 220 to 240 Vac + 10% to 15% Operating frequency 50 to 60 Hz + 6% Power consumption 13.5 VA Duty cycle 100% Operating Ambient operating temperature 5°F to 140°F (-15°C to 60°C) environment Mounting position Optional, with diaphragms in vertical position except upside down Maximum inlet gas pressure Same as VG valve Physical Weight 4.2 lb (1.90 kg) characteristics Enclosure NEMA 1, 2, 5 and 12 for indoor use NEMA 3, 3R, and 4 with sealing gasket AGA66 (only for VGG/F/D valves) Dimensions See Figure 4 Specification for valves See gas valve Technical Instructions P/N 155-512P25 Connections Conduit connection Two 1/2-inch NPSM threaded knock-outs Electrical connection Spring loaded terminals for 14 AWG wires Gas/air pressure connections 1/4” NPT Operating Output force ) 100 lb (450 N) characteristics Maximum stroke 1 inch (26 mm) Opening time for maximum stroke Varies with valve size, 14 seconds for max. stroke Closing time < 0.8 seconds Reference input signal Combustion air pressure difference Control signal Control characteristic Integral action Operation/installation Differential pressure ratio 1:1 Permissible pressure differences during operation for accurate control Gas: Minimum 0.1" w.c. Gas: maximum 80" w.c. Air: minimum 0.1" w.c. Air: maximum 80" w.c. Minimum time required for high to low fire load changes Approx. 5 seconds Permissible leakage test pressure 20 psi Permissible leakage test vacuum 3 psi Minimum diameter of impulse pipe 1/4” inside diameter Low fire bias range -0.4 to 0.4" w.c. Minimum distance of impulse pipe connections 3 pipe diameters before and 5 pipe diameters after any valve, damper, elbow, coupling, or flow disruption Auxiliary features Proof of closure switch Non-adjustable Capacity of auxiliary switch 6 (3) A, 250 Vac Setting range of auxiliary switch 40% to 100% of stroke Siemens Building Technologies, Inc. Page 3 Technical Instructions SKP55 U.. Air/Gas Ratio Controlling Actuators Document No. 155-753 July 9, 2014 Operation The electro-hydraulic actuator consists of a cylinder filled with oil, and a piston containing an electric oscillating pump and a relief system. When power is supplied to the actuator (See Figure 1) the relief system closes, and the pump moves oil from the reservoir into the pressure chamber. This action causes the piston to move downward in the cylinder, opening the Safety Shut-off gas valve. When power to the pump is interrupted, the relief system opens and the gas Function valve closes in less than 0.8 seconds. A pointer, visible through the transparent portion of the terminal box cover, indicates the entire stroke range of the actuator. A light, which is visible through the lower left…