uxcell AC 110V 8P 0-60 Minutes Range Adjustable Delay Timer Time Relay AH3-3 + Base

This timer relay is constructed of typical commercial components and should provide long service life provided certain precautions are taken. It is an excellent buy for a low cost timed relay as many similar units are priced ten times higher. However, like many Pacific Rim manufacturers, this particular device’s specifications are really pushing the envelope. It is as if the marketing department is not cognizant as to how the unit is constructed and is possibly why the specifications are incomplete. Many commenters answering questions on this component also do not understand the internal electronics of this device and are merely guessing due to the schematic pictorial on the unit’s side. A few people seem to believe the device is a timed relay with double pole – double throw contacts, which is far from the truth. Others seem to think the coil voltage will work on almost anything (AC or DC at any voltage) while the actual truth is it will ONLY work on 120 V AC. When I received three of these relays for a low cost design project, the devices did not come with any paperwork as to specifications, connections, or typical applications. The relays had a tiny label on the front stating 120 V AC, which I assumed indicated the intended coil voltage. Using the relay’s side case schematic, I connected 120 V AC to the relay’s coil (pins 2 & 7) and started to monitor the reactions at the contacts. Only then did the confusion really set in. My background was as a lead development electrical engineer for a Fortune 500 computer company for 25 years. Even though now retired, I am well versed in all types of electronics and decided an investigation of the internal workings would be necessary if I was to use this device. I spent an afternoon disassembling and developing the actual internal schematic. My general findings are as follows and should help anyone wanting to use these relays. The defined coil pins feed an internal common step-down AC transformer (120 to 24 V AC) that is used to power the relay’s internal electronics. Using a transformer removes any possibility of using DC to power this unit. After the transformer, the low voltage AC is rectified to provide DC power to the timer circuit (an LM8445) and TWO internal SPDT relays, which in turn connect to the external contacts per the relay’s side schematic. One internal DC relay ACTIVATES IMMEDIATELY when the main device’s coil receives its 120 V AC. It would be similar to a standard 120 V AC coil relay operating with single pole – double throw contacts (1C) - Output pin 1 (common), pin 3 (normally open), pin 4 (normally closed). This first relay is unaffected by any timing operation and switches off when AC power is removed from the relay coil pins. The second internal relay is activated by the relay’s internal timing circuit where the delay is determined by the external knob (seconds to one hour). The relay case schematic shows these output pins as – Pin 8 (common), Pin 5 (normally closed), and pin 6 (normally open). This internal DC relay activates upon completion of the internal delay timer. The two small LEDs next to the timing knob show the state of the timing circuit. When power is first applied, the LED ON illuminates. When the timing circuit completes, the LED ON light extinguishes and the LED UP turns on from its previous non illuminated state. Side Note: This relay requires voltage on the coil pins to operate. Removal of the coil voltage will almost immediately reset both the internal relays to their off state. No timing operation can occur without AC relay coil power as the internal DC source voltage disappears within milliseconds. Contact clarification: The internal 24 V DC relays used in my device were Omron G6E-134P components. These are well known devices within the electronics industry but their contacts are rated at 2 Amperes resistive at up to 250 V. AC. They are primarily to be used for signaling (triggers for higher current switching devices). In other words, these relays are not intended for any significant loads such as motors or high draw lighting circuits. The external case wording indicates the device can switch 5 ampere loads but that is in major contradiction to the Omron relay specification. Conclusion: This device is a fairly well built timing relay but it will not switch significant loads of more than an ampere or possibly two. Using this device to directly drive motors or other heavy inductive or even resistive loads will shorten its life considerably. In spite of these shortcomings, this timing relay is an excellent buy compared to other similar commercial units. In my application where the switched current will be low, I am confident these relays will have a long life span.

Back in 2014, "Camera Buff" did an excellent review of these timers, but things have changed. I purchased this on Oct., 14, 2023 and have found that the Relays inside the timer are rated at 10 Amps, 125 volts. After opening the case, I was able to photograph the top of the first relay. In the first image, I used Photoshop to expand the label on the relay. You can plainly see the model number and 10 Amp rating. The next image shows the second relay, behind the first one, is the same. As long as the ratings are true, this is a huge increase from the much older version, in 2014. FWIW - I searched for the ZD-3FF-S-1Z relays and found each ONE selling for far more that the price of this whole relay. I would say this is a very good deal. It should easily provide a delay for my 200 Watt RV Refrigerator! Oct., 28 Update: The delay relay is working great. I have it set for about a 2 minute delay and it works every time. When running the refrigerator on the Generator, the "Passthrough" is active (my install), and the Gen supplies the power. When I shut off the Gen, the relay senses a short interruption and immediately begins the 2 min delay, for compressor protection. I'm happy I found this Delay Relay!

Good item

Worked just like its described. I used it to prevent power from bouncing for computer server.

Wiring illustrations for 120 Volt AH3-3 timer: http://waterheatertimer.org/How-to-wire-AH3-3-timer.html Timer coil voltage 120V AC. Contacts rated 3 amp at 240 Volt -or- 6 amp at 120 Volt Volts x amps = watts/ 6 amp x 120 volt = 720 watts Max 1/4 HP: bath fans are usually 1/6 Hp or 1/3 Hp. Recirculation pumps 1/25 Hp. 1/3 Hp attic fans are probably to large amp draw for this timer to operate long-term. For long term, keep load amp draw smaller than load rating... or connect timer to contactor and let contacor handle heavy amp load Timer can be used as relay, ON-delay, OFF delay, or all 3 at same time. 0-60 minute settings are approximate... experiment to fine turn setting. 8-pin base included with 8 screw terminals. Remove timer from base to attach wires. Size: 2-1/2" tall with base included x 1-5/8" x 2" Base can be mounted on din rail, or with two screws or bolts Timer activates when 120 V AC power is connected to terminals 2 and 7. Connect white neutral and black hot to either terminal 2 or 7. With DC models of this timer, then connect - to terminal 2 and + to terminal 7 For off delay connect 120 V hot to terminal 8, and load hot to terminal 5. Connect load neutral to neutral For on delay connect 120 V hot to terminal 8 and load hot to ternminal 6. Connect load neutral to neutral For ordinary relay connect 120 V hot to terminal 1 and load hot to terminal 4. Connect load neutral to neutral... relay will remain On as long as power is applied to timer terminals 7 and 2 Wiring illustrations http://waterheatertimer.org/How-to-wire-AH3-3-timer.html

how can only 25% work of two ordered relays you might wonder? well one is completely dead out of the box. the other one works half. on one side the contacts switch on/off on the other side they are just solid, no change of state. If I plug the other one into that socket where the one works one-sided then it's completely dead, so I know it is not the wiring. Also it is upside-down. On a DIN rail you have the clip that locks at the bottom, if the relay is installed that way you will have the dial and writing upside down. Not a big deal but says a lot about the design.

Pour un système de sécurité.

bien reçus tel que décrit

Good

very good thanks

Buen producto