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Discontinued Products
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Dimensions
- Unit: mm in
General tolerance : ±0.5 ±0.20
Panel Mount Dimensions(with mounting frame)
Surface Mount Dimensions
Panel Cut Out Dimensions
Standard cut out dimensions are shown below.
Use mounting frame (AT8-DA4) and rubber gasket (ATC18002).
Adjacent Mounting
*1 The proper thickness of mounting panel is between 1 to 5mm.
*2 Adjacent mount is less water-resistant.
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Wiring/ Connection
PM4H-A
Pin type
Timed-out 2 Form C
Screw terminal type
Timed-out contact 2 Form C
PM4H-M
Pin type
Timed-out 1 Form C
Instantaneous 1 Form C
Screw terminal type
Timed-out 2 Form C
Instantaneous 1 Form C
PM4H-S
Pin type
Timed-out 2 Form C
Screw terminal type Timed-out 2 Form
Note)
1. DC Type
| Type | Pin | Screw terminal |
|---|---|---|
| PM4H-A | Connect the terminal (2) to negative (-), and the terminal (10) to positive (+). | Connect the terminal [2] to negative (-), and the terminal [1] to positive (+). |
| PM4H-S PM4H-M | Connect the terminal (2) to negative (-), and the terminal (7) to positive (+). |
2. Contact
3. Voltage should not be applied to the various inputs (reset, start, and stop) of the PM4H-A multi-range timer. These inputs should be input without voltage.
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Cautions For Use
Timers Cautions for Use (Common for All Models)
Cautions for circuits
1.Protective circuit for timer contact
In the circuit that switches an inductive load, a contact failure may occur at a contact point due to surge or inrush current resulting from that switching.
Therefore, it is recommended that the following protective circuit be used to protect the contact point.
| Circuit | Application | Features/Others | Device Selection | |||
|---|---|---|---|---|---|---|
| AC | DC | |||||
| CR circuit (r: resistor c: capacitor) |  | * Note: | Available | If the load is a relay or solenoid, the release time lengthens.Effective when connected to both contacts if the power supply voltage is 24 or 48 V and the voltage across the load is 100 to 200 V. | If the load is a timer, leakage current flows through the CR circuit causing faulty operation. Note: If used with AC voltage, be sure the impedance of the load is sufficiently smaller than that of the CR circuit. | As a guide in selecting r and c, c: 0.5 to 1 µF per 1 A contact current r: 0.5 to 1 ohm; per 1 V contact voltage Values vary depending on the properties of the load and variations in timer characteristics. Capacitor c acts to suppress the discharge the moment the contacts open. Resistor r acts to limit the current when the power is turned on the next time. Test to confirm. Use a capacitor with a breakdown voltage of 200 to 300 V. Use AC type capacitors (non-polarized) for AC circuits. |
| - | ||||||
 | Available | Available | ||||
| Diode circuit |  | N/A | Available | The diode connected in parallel causes the energy stored in the coil to flow to the coil in the form of current and dissipates it as joule heat at the resistance component of the inductive load. This circuit further delays the release time compared to the CR circuit.(2 to 5 times the release time listed in the catalog) | Use a diode with a reverse breakdown voltage at least 10 times the circuit voltage and a forward current at least as large as the load current. In electronic circuits where the circuit voltages reverse breakdown voltage of about 2 to 3 times the power supply voltage. | |
| Varistor circuit |  | Available | Available | Using the rated voltage characteristics of the varistor, this circuit prevents excessively high voltages from being applied across the contacts. This circuit also slightly delays the release time. Effective when connected to both contacts if the power supply voltage is 24 or 48 V and the voltage across the load is 100 to 200 V. | - | |
2.Type of Load and Inrush Current
The type of load and its inrush current characteristics, together with the switching frequency are important factors which cause contact welding. Particularly for loads with inrush currents, measure the steady state current and inrush current and use a relay or magnet switch which provides an ample margin of safety. The table below shows the relationship between typical loads and their inrush currents.
| Type of load | Inrush current |
|---|---|
| Resistive load | Steady state current |
| Solenoid load | 10 to 20 times the steady state current |
| Motor load | 5 to 10 times the steady state current |
| Incandescent lamp load | 10 to 15 times the steady state current |
| Mercury lamp load | 1 to 3 times the steady state current |
| Sodium vapor lamp load | 1 to 3 times the steady state current |
| Capacitive load | 20 to 40 times the steady state current |
| Transformer load | 5 to 15 times the steady state current |
When you want large load and long life of the timer, do not control the load direct with a timer. When the timer is designed to use a relay or a magnet switch, you can acquire the longer life of the timer.
3.Connection of input
Since PM4H and LT4H series timers use a transformerless power supply system, the input equipments must have the power supply transformer in which the secondary side is not grounded with the primary and secondary sides insulated, in order to prevent interference of the power supply circuit when connecting the external input circuit as Fig. A.
Be sure not to use an autotransformer. In case of secondary side grounded or using the autotransformer, this product may be destroyed due to short circuit electrically as Fig. B (1 and 2).
In case of F.G. terminal of equipments such a PLC grounded in secondary side of the transformer, inner circuits of this product and the input equipment may be destroyed due to short circuit electrically as Fig.B (3).
Therefore, use the isolated type timers or do not ground F.G. terminal of the products.
4.Long Continuous Current Flow
Long continuous current flow through the timer (approx. one month or longer) cause generation of heat internally, which degrade the electronic parts. Use the timer in combination with a relay and avoid long continuous current flow through the timer.
When using contact output
When using non-contact output
5.Leakage current
6.Power off time
If the operation voltage for the timer is turned ON after the limit time operation is completed or before the limit time is reached, the Power off time longer than the timer restoration time must be secured.
7.Suicide circuit
If the timer is restored immediately after the specified time is reached, the circuit must be configured so that the restoration time of the timer can be secured sufficiently.
If the power circuit for the timer is turned OFF with the timer contact, a suicide circuit may be configured (Fig. A). In order to settle the problem with this potential suicide circuit, the circuit must be designed so that the timer is turned OFF after the self-retention circuit is completely released (Fig. B).
8.Electrical life
The electrical life varies depending on the load type, the switching phase, and the ambient atmosphere. In particular, the following cases require careful attention:
1.If an AC load is switched in synchronized phases:Locking or welding is liable to occur due to contact transposition. Check this with the actual system.2.If a load is switched very frequently:
If a load which generates arcs when a contact is switched is turned ON and OFF very frequently, nitrogen and oxygen in air are combined due to arc energy and then HNO3 is produced. This may corrode metallic materials.
The effective countermeasures include:
- 1.Using an arc-extinguishing circuit;
- 2.Decreasing the switching frequency; and
- 3.Decreasing the humidity in the ambient atmosphere.
9.Pin connections
Correctly connect the pins while seeing the pin layout/connection diagram. In particular, the DC type, which has polarities, does not operate with the polarities connected reverse. Any incorrect connection can cause abnormal heating or ignition.
10.Connection to operation power supply
2. The operation voltage for the DC type must be at the specified ripple percentage or less. The average voltage must fall within the allowable operation voltage range.
| Rectification type | Ripple percentage |
|---|---|
| Single-phase, full-wave | Approx. 48% |
| Three-phase, full-wave | Approx. 4% |
| Three-phase, half-wave | Approx. 17% |
11.Control output
2. The following connection might result in short circuit between the heteropolar contacts in the timer.
12.Installing the timer
2. In order to maintain the characteristics, do not remove the timer cover (case).
13.Superimposed surge of power supply
For the superimposed surge of power supply, the standard waveform (±1.2×50μs or ±1×40μs) is taken as the standard value for surge-proof voltage.
(The positive and negative voltages are applied each three or five times between the power pins.) For the standard values for the PM4H, LT4H, and S1DX type timers, see the respective items in "Caution on usage."
Single-pole, full-wave voltage for surge waveform[±(1.2×50)μs]
Single-pole, full-wave voltage for surge waveform[±(1×40)μs]
PMH [±(1×40)μs]
| Voltage type | Surge voltage |
|---|---|
| AC type (except 24V AC) | 4,000V |
| 12V, 24V DC, 24V AC | 500V |
Other timers [±(1×40)μs]
| Type | Surge voltage |
|---|---|
| PNS CN-C CHP, CHP-F | 20 times rated voltage |
| CHP-SD | 4,000V |
If external surge occurs exceeding the specified value, the internal circuit may break down. In this case, use a surge absorption element. The typical surge absorption elements include a varistor, a capacitor, and a diode. If a surge absorption element is used, use an oscilloscope to see whether or not the foreign surge exceeding the specified value appears.
14.Changing the set time
Do not change the set time when the limit time operation is in progress.
However, this is possible only with the motor-driven type timer if the set time is shorter than the remaining time. For changing the set time on the digital timer (LT4H), see the relevant item in "Caution on use."
15.Operating environment
2. Avoid using the timer in a locationwhere (a) inflammable or corrosive gas is generated, (b) the timer is exposed to much dust and other foreign matter; (c) water or oil is splashed on the timer; or (d) vibrations or shocks are given to the timer.
3. The timer cover (case), the knobs, and the dials are made of polycarbonated resin. Therefore, prevent the timer from being exposed to organic solvents such as methyl alcohol, benzine, and thinner, strong acid substances such as caustic soda, and ammonia and avoid using the timer in atmosphere containing any of those substances.
4. If the timer is used where noises are emitted frequently, separate the input signal elements (such as a sensor), the wiring for the input signal line, and the timer as far as possible from the noise source and the high power line containing noises.
16.Checking the actual load
In order to increase the reliability in the actual use, check the quality of the timer in the actual usage.
17.Others
2. If any malfunction of the timer is likely to affect human life and properties, give allowance to the rated values and performance values. In addition, take appropriate safety measures such as a duplex circuit from the viewpoint of product liabilities.
PM4H Series Cautions For Use
1.Input connections (PM4H-A type)
2. When one input signal is simultaneously applied to more than one timer, be sure to avoid the wiring shown in Fig. E.Otherwise, the short-circuit current will flow and cause damage. Be sure to align the polarity of the power supply as shown in Fig. F.
3. Terminal (2)-(6) (screw terminal [2]-[3]) should be connected as the start input. Connect terminals (2)-(7) (screw terminal [2]-[4]) for reset signal input. Connect terminals (2)-(5) (screw terminal [2]-[5]) for stop signal input. Be sure not to connect with other terminals and apply excessive voltage. The internal circuit will be damaged.4.The input wiring other than the power supply circuit should avoid these conditions,high-voltage wiring and parallel wiring with power wire. Wire in short with using the shielding wire or metal wiring tube.
5.For start, reset and stop input, use gold-plated contact with high reliability. Since contact bouncing causes errors in the start, use an input contact less bounce time.
6.Keep the minimum signal input times over 0.05s.
2.Input signal conditions(PM4H-A type)
Use gold-plated contacts with high-reliability. The bounce time at the contacts causes errors in the timer operation time. Accordingly, use start input contact whose bounce time is short. The resistance when shorted should be less than 1kohm;, and when open resistance should be more than 100kohm. For the screw terminal type, connect the terminal [2] to the each input signal.
2.Connection of contact input (Pin type example)
Apply the open-collector connection. The characteristics of the transistor used must be VCEO=10V or more, IC=10mA or more, and ICBO=6µA or less. Additionally, the input impedance must be 1kohm; or less, and the residual voltage must be 0.6V or less. For the screw terminal type, connect the terminal [2] to the each input signal.
3.Connection of non-contact input (Pin type example)(voltage input)
Even if the open collector is not used, input is also possible from the non-contact circuit of 6 to 30V DC. In this case, the start input is turned on when the signal is turned from H to L. The residual voltage must be 0.6V or less when Q is on. On the AC type, an insulated transformer is required as the power supply for the photoelectric sensor, etc. (power supply for the input devices).
Keep the minimum input signal time of each signal to 0.05s or more.
3.Checking the contacts before use (PM4H-F only)
When the power ON time is less than the minimum power application time, the contacts may remain in an ON state, so the state of the contacts should be checked before use. When the contacts are in an ON state, activating them once will return them to their normal state (the OFF state after time-out). (Be aware that relay characteristics may result in the contacts being in that same ON state if exposed to excessive vibration and impact during transport.)
4.Time setting
To set the time, turn the set dial to a desired time within the range. Instantaneous output will be on when the dial is set to "0". When the instantaneous output is used, the dial should be set under "0" range.(Instantaneous output area)
Note) When power supply is on, the time range, setting time and operation mode cannot be changed. Turn off the power supply or a reset signal is applied to set the new operation mode.If the position is not stable, the timer might mis-operate.
5.Superimposed surge of power supply (PM4H series common)
For the superimposed surge of power supply, the standard waveform is taken as the standard value for surge-proof voltage. If external surge occurs exceeding the specified value, the internal circuit may break down. In this case, use a surge absorption element.
| Operating voltage | Surge voltage(peak value) |
|---|---|
| 100 to 240V AC 100 to 120V AC 200 to 240V AC 48 to 125V DC | 4,000V |
| 12V DC, 24V DC 24V AC/DC | 500V |
The positive and negative voltages are applied each five times between the power pins. The typical surge absorption elements include a varistor, a capacitor, and a diode. If a surge absorption element is used, use an oscilloscope to see whether or not the foreign surge exceeding the specified value appears.
6.Acquisition of CE marking
Please abide by the conditions below when using in applications that comply with EN61812-1.
1.Overvoltage category III, pollution level 2
2.This timer employs a power supply without a transformer, so the power and input signal terminals are not insulated.
- 1. When a sensor is connected to the input circuit, install double insulation on the sensor side.
- 2. In the case of contact input, use dualinsulated relays, etc.
3.The load connected to the output contact should have basic insulation.
This timer is protected with basic insulation and can be double-insulated to meet EN/IEC requirements by using basic insulation on the load.