Instruction Sheet Replacing a Gun Thermostat WARNING: Allow only qualified personnel to perform the following tasks. Observe and follow the safety instructions in this document and all other related documentation. 1. Introduction Thermostats are used to control the temperature of some Nordson applicators, hoses, and guns. This instruction sheet provides the procedure for replacing the thermostat in Nordson thermostat-controlled guns. Thermostat Use this procedure for thermostat-controlled guns only. The thermostat is usually mounted with two screws on the manifold body. WARNING: Hot! Risk of burns! Hot applicator parts, splashed hot melt material, and hot gun surfaces can cause severe burns. Wear long-sleeved, heat-protective clothing, safety goggles, and heat-protective gloves. Hot melt material may be released forcefully. WARNING: Risk of burns. System or material pressurized. Air trapped in hoses and guns can spit out molten adhesive that can cause severe burns. Failure to relieve hydraulic pressure can result in serious burns. Relieve hydraulic pressure when instructed to do so. WARNING: Even when switched off, Nordson applicators, hoses, and guns contain electrical potentials that can cause death. Disconnect and lock out line voltage to the applicator when instructed to do so.
2 Replacing a Gun Thermostat Thermostat (contd.) 1. Relieve hydraulic pressure by following the instructions in the applicator manual. 2. Move the applicator circuit breaker to the OFF position, then disconnect and lock out input electrical power to the applicator. Fig. 1 Typical Facility and Applicator Circuit Breakers 4201088 3. Disconnect the gun electrically from the hose. 4. Use two wrenches to disconnect the hose from the gun. Place one wrench on the gun fitting and one on the hose fitting. 5. Remove the manifold body cover screws, then move the cover away from the manifold body. 6. Make a note of the wire connections for reference when installing the new thermostat. CAUTION: Be sure to connect the gun wiring correctly. Connecting the wiring incorrectly can cause equipment damage or system failure. Fig. 2 Typical Manifold Body Cover 4201046
Replacing a Gun Thermostat 3 Thermostat (contd.) 7. Remove the old thermostat and replace it with the new one. Use the appropriate procedure below based on the type of wire connector you are using. Type of wire connector Wire nuts Terminal blocks and eyelets Procedure 1. Twist the exposed wires together and secure them with wire nuts. 2. Make sure the new wire connections match the previous wire connections exactly (see Figure 3). 1. Strip about 4.75 mm ( 3 / 16 in.) of insulation from each wire to be connected. 2. Insert each wire into an eyelet (one wire per eyelet). 3. Insert the eyelets into terminal blocks. 4. Make sure the new wire connections match the previous wire connections exactly (see Figure 3). 5. Secure and crimp the eyelets by tightening the terminal block screws. Torque to approximately 70 in-oz. NOTE: It does not matter which new thermostat wire is connected to which heater or cordset wire because the thermostat is not polarity-sensitive. 1 4 2 3 2 5 3 1 5 4 4201080 Fig. 3 Schematic of Typical Thermostat Wire Connections 1. Cordset 2. Ground connection 3. Terminal block (or wire nut) 4. Heater 5. Thermostat
4 Replacing a Gun Thermostat Thermostat (contd.) 8. If desired, install the thermostat cover. The cover protects the thermostat from short circuiting. CAUTION: When reinstalling the manifold body cover, do not pinch the wires between the cover and the manifold body. Pinched wires can cause the gun to fail. 9. Replace the manifold body cover and secure it with the cover screws. 10. Use two wrenches to reconnect the gun to the hose. Place one wrench on the gun fitting and the other on the hose fitting. 11. Reconnect the gun electrically to the hose. 12. Restore the system to normal operation by following the instructions in the applicator manual.
Replacing a Gun Thermostat 5 3. Parts To order parts, call the Nordson Customer Service Center at 800-241-8777 or contact your local Nordson representative. Use the following parts lists to describe and locate parts correctly. Table 1 Thermostat Replacement Kits Part Description Quantity Note 271 928 Kit, Thermostat, 325 _F A 271 929 Kit, Thermostat, 350 _F A 271 930 Kit, Thermostat, 375 _F A 271 931 Kit, Thermostat, 400 _F A 271 932 Kit, Thermostat, 425 _F A 271 933 Kit, Thermostat, 225 _F A 271 934 Kit, Thermostat, 250 _F A 271 935 Kit, Thermostat, 275 _F A 271 936 Kit, Thermostat, 300 _F A 271 937 Kit, Thermostat, 450 _F A 272 825 Kit, Thermostat, 350 _F B 272 826 Kit, Thermostat, 375 _F B NOTE A: This kit includes a thermostat cover (P/N 273 555). Covers may be ordered separately. B: This kit does not include a thermostat cover. Table 2 Terminal Blocks and Eyelets Part Description Quantity Note 226 769 Eyelets, Package of 25 1 A 939 994 Connector Assembly, Plastic, 1-Station (Terminal Block) 1 B NOTE A: Eyelets will be needed if you are replacing a thermostat on a gun that has terminal blocks. The thermostat replacement kit does not include eyelets. B: Order terminal blocks only if you are switching from wire nuts to terminal blocks. Eyelets must be ordered separately. Original copyright date 1997. Nordson and the Nordson logo are registered trademarks of Nordson Corporation.
6 Replacing a Gun Thermostat