Small Push Pull Solenoids

1. Design and Features
The small push-pull solenoids have the same features as the conventional push-pull solenoid. The push-pull solenoid design utilizes a coil with the maximum amount of magnet wire in the smallest amount of space. This coil assembly is then packaged in a metal housing using highly permeable steel to obtain the maximum force in the minimum size and weight. This small size solenoid is a very cost-effective solution when small movements are required and/or limited amount of electrical power is available.

2. Stroke and Force
The conical pole piece configuration is the standard design for the small push-pull solenoid. For the best performance efficiency, the stroke should be kept to a minimum.

3. Operational Consideration
A) Temperature
The coil data of small push-pull solenoids shows the values at ambient temperature 20°C and without the use of a heat sink. If a solenoid is used at a rating shown in the coil data, it is designed so that the coil temperature rises and reaches equilibrium at approximately 85°C. In applications where the ambient temperature is higher than 20°C possible thermal damage can occur. Temperature rise tests should be performed by the customer to assure that the coil does not reach 120°C. Coils can be constructed to operate at temperatures higher than 120°C without thermal damage. Please consult the factory for details.
B) Air Gap Spacer
The small push-pull solenoid uses an air gap spacer between the armature and the case. This spacer is installed to prevent the armature and base from coming into mechanical contact with each other, would cause residual magnetism.
C) Return Spring
The small push-pull solenoid does not include a return spring. Therefore, the application must include a return spring.
D) Shaft Modification
It is not recommended that the customer modify the shaft, as the shafts are fabricated before assembly. Any special configuration can be supplied. Please consult factory for details.
E) Installation of Solenoid
The small push-pull solenoid uses tapped holes for mounting in the base. Caution needs to be observed that the mounting screws used to attach these solenoids are the correct length so as not to damage the coil.

4. General Characteristics
Insulation class: Class E (120°C), Size 110C is class A (105°C), Lead wire class A (105°C)
Dielectric strength: AC 1000V 50/60 Hz 1 min. (at normal temperature and normal humidity)
Insulation resistance: More than 100 Megohm at DC 500V megger (at normal temperature and normal humidity)
Expected life Standard life: 5 million cycles (Solenoid cycle life is very dependent upon side load, frequency of use, and environmental conditions. Cycle life tests should be performed by the customer.)

5. How to Select a Solenoid
Before selecting a small push-pull solenoid, the following information must be determined:
A) Force
The actual force required in the application should be increased using a safety factor multiplier of 1.5 to arrive at the force value that should be used in your specification.
B) Duty Cycle
Use the aforementioned formula to calculate duty cycle. Also note the maximum on time.
C) Stroke
Stroke is determined by application and requirements.
D) Operating Voltage
Operating DC voltage is determined by the application and voltage available. After determining these specifications, one can find the correct size solenoid for the application, using the force-stroke characteristic tables and graphs. The coil data is also shown for different sizes of magnet wire. If the exact operating voltage is not in the coil data table, please consult the factory for details. To determine the force output of the solenoid after temperature rise, please use the amp-turn force graphs after calculating the amp-turns.

6. Ordering information
When ordering a small push-pull solenoid, the correct part number needs to be determined from the following combination of characteristics(1-3):
(1) M-Metric thread or F-SAE thread
(2) Solenoid size (example-144C)
(3) Coil voltage from tables (At 100% duty cycle)
Example of a complete part number.
(1) (2) (3)
M 144C-6V
This part number is for a solenoid with Metric threads, size 144C,with a 6V coil.